Source: COLORADO STATE UNIVERSITY submitted to NRP
INTRODUCTION, ADAPTABILITY, PRODUCTION AND SURVIVAL OF LANDSCAPE PLANTS IN COLORADO
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0155041
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Jul 1, 2008
Project End Date
Jun 30, 2013
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
COLORADO STATE UNIVERSITY
(N/A)
FORT COLLINS,CO 80523
Performing Department
Horticulture and Landscape Architecture
Non Technical Summary
Summary [1] Improper selection of landscape plant material can result in financial loss and dissatisfaction to homeowners and industry personnel. 2A] Research will define safe, effective herbicides and modified container production techniques.[2B] Identifying actual water requirements of ornamental grasses and woody plant shrub species will benefit homeowners and industry in considerable water savings.[2C] Proper tree planting and production techniques can result in higher percentage of tree survival in the landscape.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1022110106010%
2022110106020%
2022120106010%
2022123106030%
2052110106020%
2052300114010%
Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships; 205 - Plant Management Systems; 202 - Plant Genetic Resources;

Subject Of Investigation
2110 - Ornamental trees and shrubs; 2123 - Bedding/garden plants; 2120 - Herbaceous perennials and decorative greens; 2300 - Weeds;

Field Of Science
1060 - Biology (whole systems); 1140 - Weed science;
Goals / Objectives
Goals/Objectives 1. Selection, introduction and evaluation of herbaceous annuals, herbaceous perennials including ornamental grasses and woody plant material for growing in the Rocky Mountain and High Plains Region including Plant Select and native plant material. 2. Conduct cultural studies related to adaptability, production and survival of landscape plants in Colorado which can include: 2A. Weed control studies to aid in overall production of container-grown landscape plants. 2B. Evaluate and determine water requirements of ornamental grasses and landscape woody plants. 2C. Evaluate various nursery production procedures and establishment of woody plants in the landscape.
Project Methods
Methods Selection, introduction and evaluation of herbaceous plant material for growing in the Rocky Mountain and High Plains region, including Plant Select. Trial planting of annuals, herbaceous perennials, ornamental grasses and woody plants will continue to be conducted in Fort Collins to determine which plants are best suited for the Rocky Mountains and High Plains area. Plant Select, a cooperative plant introduction and recommendation program between Colorado State University, Denver Botanic Gardens and Green Industries of Colorado, whose purpose is to increase the diversity of commercially available plants best suited for the Rocky Mountain and High Plains region, will continue to identify, select, test, produce, introduce, and promote outstanding new plants adapted for landscape use. Criteria have been established for identification, selection and testing these outstanding new plants. 2A. Weed control studies to aid in overall production and establishment of landscape plant material. Experiments studying the effect of herbicide types and rates especially with container grown herbaceous perennials and some woody nursery stock will continue. New and standard herbicides and several combinations will be evaluated for their effectiveness and weed control phytotoxicity and effect on plant growth. 2B. Water requirements and abiotic factors of certain woody shrub and ornamental grass species are being researched to understand how some species adapt better to certain climatic and cultural conditions in Colorado and the region. In the drought tolerance field study, ornamental grasses will be subjected to four different amounts of supplemental irrigation (100 percent, 50 percent, 25 percent and 0 percent of ET) Numerous woody plant species with varying degrees of estimated drought tolerance will also be tested. 2C. In 2010, Pyrus calleryana bare root trees were planted into three container types. Temperature measurement in the growing media will be recorded throughout winter and summer along with taking various growth data on all plants. Leaf water potential and leaf canopy temperature will be taken throughout growing season. These trees will then be transplanted into bluegrass turf and will grow in this landscape site for 1, 2 and 3 years after initial planting. Same growth measurements will be taken yearly along with leaf water potentials. Trees will be harvested 1, 2 or 3 years after planting and roots will be exposed using an air spade.

Progress 07/01/08 to 06/30/13

Outputs
Target Audience: Green Industry personnel, Extension personnel, homeowners and gardeners Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Various training opportunities were developed including field days, short courses, tours, industry presentations and one-on-one training with green industry personnel, state and county extension personnel along with interested homeowners.® How have the results been disseminated to communities of interest? Colorado State University Research Updates are published six times per year in two state publications entitled Colorado Green and Colorado Nursery and Greenhouse Association Looseleaf. Presentations on this research are given yearly at state Green Industry Conference entitled "ProGreen". Annual and perennial flower evaluations are published yearly performance reports made available in both hard copy and electronic versions. Web sites have been developed for most of these research areas including annual flower trials, herbaceous perennial trials, woody plant evaluation and Plant Select®. Technical reports ahve been written about both annual and herbaceous perennial trials. Scietific research articles ahve been published in peer-reviewed publichations on weed control, water requirements of woody ornamental plants and green roof suitable plants and media for green roof in a semi-arid climate. What do you plan to do during the next reporting period to accomplish the goals? This is a terminal report for this project but herbaceous (annuals and perennials) and woody plants is on going. Research with herbicides on minor crops is on going and water related studies have shifted from woody plants to ornamental grasses. Additional cultural studies evaluating nursery production procedures of woody plants in the landscape will be established.

Impacts
What was accomplished under these goals? From #1 - In the past five years over 33 Plant Select® plants have been either introduced or recommended to Colorado and Rocky Mountain Region. Since 2008, over five thousand different annual flower varieties have been evaluated and "Best Of's" chosen and promoted to both industry personnel and homeowners. Herbaceous perennials recently introduced in the trade (approximately 150) have been evaluated and five to ten "Top Performers" chosen yearly and promoted to industry and homewners. Approximately eighteen hundred different taxa of woody plants are evaluated yearly for landscape adaptability and various ornamental characteristics. A technical report on "Top performing trees", both deciduous and evergreen has been written and is being published in early 2014. 2A. Weed control studies with herbaceous perennials have been conducted since 2008. Yearly four to six different herbicides are applied to ten to fifteen different herbaceous perennials to evaluate potential phytotoxicity. This research has lead to registration for numerous chemicals for use on minor crops especially herbaceous perennials. 2B. Water requirements of woody and herbaceous plants have lead to knowledge of exact water requirements of various woody landscape shrubs providing property managers and homeowners and industry personnel monetary savings by ultimately conserving water use. 2C. Plants native to Colorado, which grow in areas with shallow, well-drained soils can be used for green roof plants. Numerous Colorado natives have been found to be good plants for green roofs along with certain growing media. These are now recommended for green roofs in a semi-arid region.

Publications

  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Smith, Jason and James Klett 2013. Responses of Four Common Shrub Species to Different Irrigation Regimes. J. Environ. Hort. 321(4) 211-220.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Klett, James E. 2013. CSU Update Announcing Plant Select� 2013. CNGA Looseleaf 31(1) 18-19.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Klett, James E. and Lindsey Greeb 2013. CSU Update Hardy Perennials for Colorado Landscapes. CNGA Looseleaf 31(2) 18-19.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Klett, James E. and Jane Rosum 2013. CSU Update Best Ornamental Grasses for the Colorado Climate. (CNGA Looseleaf 31(3) 15.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Klett, James E. 2013. CSU Update Woody Plant Evaluations. CNGA Looseleaf 3194) 18-19.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Klett, James E. 2013. CSU Update 2013 Superior Perennials. CNGA Looseleaf 31(6) 20-21.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Klett, James E. 2013. CSU Research Update - Spring Preview: Plant These Winning Annuals. Colorado Green 29(1) 14-15.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Klett, James E. 2013. CSU Research Update - Try These Top Performing Perennials. Colorado Green 29(2) 12-13.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Klett, James E. 2013. CSU Research Update - Try These Xeric Woody Plants. Colorado Green 29(3) 10-11.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Klett, James E. 2013. CSU Research Update - Outstanding Annuals for Spring. Colorado Green 29(6) 10-11.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Bousselto, Jennifer, James E. Klett and Ronda Koski 2013. Evaluating Zeolite in an Extensive Green Roof Substrate. American Nurseryman Oct., 14-21.
  • Type: Other Status: Published Year Published: 2013 Citation: Klett, J. and D. Buelow 2013. Watering and Home Landscape During Drought. Colorado State University Extension Fact Sheet 7.240.


Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: Woody and herbaceous plants continue to be evaluated for adaptability to the High Plains on a 30 ha site. Woody (45 taxa) and herbaceous plants (116 taxa) were acquired in 2012 for evaluation. Performance records for 2905 taxa of woody and herbaceous plants were entered into a computer system, which are available on three websites. Approximately 1020 varieties of annual flowers and 118 varieties of herbaceous plants were evaluated in 2012. In 2012, six plant species were recommended or introduced by Plant Select. Over 80 demonstration gardens are displaying Plant Select plants throughout Colorado. The multi-site woody plant trial continued at four locations throughout the state with 4 additional taxa planted in 2012. Various container productions systems for nursery stock are being evaluated to observe root malformations and transplant success of Pyrus calleryana 'Glen's Form' as influenced by container types and overwintering treatment. After two years of growth, there were no significant effects of container type on height, caliper, leaf dry weight, and shoot and root measurements except for percent of re-growth. Root Pouch and Smart Pot both resulted in more root re-growth than black plastic container. Visually, the root systems are very different in root architecture, since Root Pouch and Smart Pot roots are more highly branched and less prone to circling, compared to black plastic. Five herbicides: Biathlon (OHP 052908), F6875SC, Freehand (BAS659HG), Gallery 75DF and Indoziflom G were evaluated for weed control effectiveness and phytotoxicity on seven different herbaceous perenials and annuals with the experiment repeated twice in Fort Collins. Biathlon and Gallery applied at three different rates had no adverse effects on three different plant taxa. Freehand G resulted in chlorosis at all three rates applied on Helianthus salicifolius 'Low Down'. Indaziflom G did result in some phytotoxicity especially chlorosis at higher rates with Sedum spurium "Dragon's Blood' and Delosperma cooperi. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Specific performance results from these annual, perennial and woody plant trials help determine which new and superior annual and perennial varieties growers throughout the state and region should grow and market. A performance report for annuals and perennial trials was published and posted on websites and sent to all cooperators and industry personnel in the state and region. Many seed and vegetatively propagated varieties including Sun-New Guinea Impatiens, coleus and dahlias have become important bedding plant crops in the state due partially to this research. Plant Select plants, which are either introductions or recommendations were promoted throughout the state and region. In 2012, over 1.6 million Plant Select plants were sold and over 500 thousand people visited over 80 demonstration gardens. Weed control research with container grown plants help growers control weeds considerably cheaper than hand pulling, which ultimately lowers the cost of production which is passed on to consumers. Knowledge of exact water requirements and adaptability of ornamental grasses provides property managers and homeowners monetary savings by ultimately conserving water use. Root systems of woody plants grown in Root Pouch and Smart Pot containers had more highly branched roots with less circling which could lead to easier establishment and less girdling roots causing problems with established wood plants in future years.

Publications

  • Bousselot, J., Klett, J., and Koski, R. 2012. Evaluating a Natural Zeolite as an Amendment for Extensive Green Root Substrate, Journal of Environmental Horticulture. 30(4):201-206.
  • Klett, J. 2012. 2012 Flower Winners. CSU Research Update, Colorado Green. 28(1):16-17.
  • Klett, J. 2012. Perennials that Pack a Punch. CSU Research Update, Colorado Green. 28(2):16-17.
  • Klett, J., Hammond, E. 2012. Plant Trials - Highlight Four Good Woodies and Three to Avoid, CSU Research Update, Colorado Green. 28(3) 12-13.
  • Klett, J. 2012. Exceptional Woody Plants. CSU Research Update, Colorado Green. 28(4)10.
  • Klett, J. 2012. Try These Woody Plants. CSU Research Update, Colorado Green. 28(5) 12-13.
  • Klett, J. 2012. Plant Select for 2013. CSU Research Update, Colorado Green. 28(6) 12-13.
  • Klett, J. and Greeb, L. 2012. Long lived Perennials. CSU Update. CNGA Looseleaf. 30(5) 18.
  • Klett, J. 2012. 2012 Superior Annuals. CSU Update CNGA Looseleaf. 30(6) 16-18.
  • Klett, J., Staats, D., and Freebury, P. 2012. Annual Flower Trial Garden Performance Report. 213 p.
  • Klett, J., Statts, D., and Sandoval, V. 2012. Perennial Flower Trial Performance Report. 45 p.
  • Klett, J. 2012. Horticulture Related Water Studies. Colorado Water. 29(2) 6-7.
  • Hammond, E. 2012. Multi-Site Trial of Woody Plants: 2006 Planting and Evaluation of Differences and Drought Tolerance of Three Amelanchier Species. M.S. Thesis, Spring 2012. 74 p.
  • Smith, J. 2012. Responses of Four Shrub Species to Four Levels of Irrigation in a Semi-Arid Environment. M.S. Thesis, Spring 2012. 143 p.
  • Klett, J. and Cox, A. 2012. Evergreen Shrubs, CSU Extension Fact Sheet No. 7.414.
  • Klett, J. 2012. Top Perennial Performers. CSU Update. CNGA Looseleaf. 30(2) 18-19.
  • O'Connor, A., Klett, J., and Koski, A. 2012. Nursery Tree Production and Transplant Success of Pyrus calleryana 'Glen's Form' (Chanticleer). Influenced by Container Types and Overwintering Treatment. Abstract. 2012 Conference Proceedings, International Society of Arboriculture, 88th Annual Conference, Portland, Oregon.
  • Klett, J. and Koski, R. 2012. Weed Control in Container-Grown Herbaceous Ornamental Plants. Hort Science. Supplement 47(9) ps 330.
  • Klett, J. 2012. Superior Annuals from the CSU Trials. CSU Update. CNGA Looseleaf. 30(1) 24.
  • Klett, J. and O'Connor,A. 2012. Nursery Tree Production and Transplant Success of Chanticlear Pear, CSU Update. CNGA Looseleaf. 30(3) 18-19.
  • Klett, J. 2012. Woody Plant Evaluations. CSU Update. CNGA Looseleaf 30(4) 18-19.
  • O'Connor, A., Klett, J., and Koski, A. 2012. Nursery Tree Production and Transplant Success of Pyrus calleryana 'Glen's Form' (Canticleer). Influenced by Container Types and Overwintering Treatments. Hort Science. Supplement 47(9) ps 203.


Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: Woody and herbaceous plants continue to be evaluated for adaptability to the High Plains on a 30 ha site. Woody (53 taxa) and herbaceous plants (65 taxa) were acquired in 2011 for evaluation. Performance records for 2930 taxa of woody and herbaceous plants were entered into a computer system, which are available on three websites. Approximately 1150 varieties of annual flowers and 110 varieties of herbaceous plants were evaluated in 2011. In 2011, seven plant species were recommended or introduced by Plant Select. Over 75 demonstration gardens are displaying Plant Select plants throughout Colorado. The multi-site woody plant trial continued at four locations throughout the state with 4 additional taxa planted in 2011. Four herbicides: Certainty, Echelon (F68750.3G), Freehand (BAS 659HG), and Snapshot 2.5TG were evaluated for weed control effectiveness and phytotoxicity on thirteen different herbaceous perennials and annuals with the experiment repeated twice in Fort Collins. Echelon, Freehand and Snapshot applied at three different rates had no adverse effects on the thirteen different plant taxa. However, Certainty resulted in adverse effects on the growth of some Liatris spicata. In general, weed control efficacy improved when herbicides were applied at rates greater than the labeled (1X) rate. A drought tolerance study was concluded in 2011. In the lysimeter study, the lower water treatment resulted in plants going into dormancy earlier with more winter dieback. Flowering volume with Annabelle hydrangea at the higher water rate resulted in more and larger flowers than lower rates. Both the dogwood and hydrangea need more water on a daily basis as the irrigation amount increased. This caused the plants to use the stored water in the pots at a faster rate. Water was used at a faster rate in the 100% treatment than the 25% treatment. Therefore, the amount of time that the plants were able to grow without being watered was decreased since water potential readings became more negative (more stressed) at a faster rate than the lower watered treatments. Various container production systems for nursery stock are being evaluated to observe root malformations and transplant success of Pyrus calleryana Glen's Form as influenced by container types and over-wintering treatment. Preliminary results after one season of growth showed new root growth reached the sides of black plastic pots and started to circle but this was less common in the root pouch and smart pot containers. Dry root weight did not differ significantly among container types, but root distribution in the root ball did. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Specific performance results from these annual, perennial and woody plant trials help determine which new and superior annual and perennial varieties growers throughout the state and region should grow and market. A performance report for annuals and perennial trials was published and sent to all cooperators and industry personnel in the state and region. Many seed and vegetatively propagated varieties including Argyranthemum, New Guinea Impatiens, spreading petunias and Pennisetums have become important bedding plant crops in the state. Plant Select plants, which are either introductions including two with plant patents in 2011 or recommendations were promoted throughout the state and region. In 2011, over 1.6 million Plant Select plants were sold and over one million people visited over 75 demonstration gardens. Weed control research with container grown plants help growers control weeds considerably cheaper than hand pulling, which ultimately lowers the cost of production which is passed on to consumers. Knowledge of exact water requirements of various mesic shrub species provides property managers and homeowners monetary savings by ultimately conserving water use. Growth of container landscape plants that have adjusted to decreased irrigation in the nursery could result in better plant establishment and growth when eventually planted in the landscape and exposed to lower water.

Publications

  • Klett, J. 2011. Multi-Site Woody Plant Trials. CSU Update. CNGA Looseleaf. 29(4):20.
  • Klett, J. and Greeb, L. 2011. Underused Perennials for Colorado. CSU Update. CNGA Looseleaf. 29(6):20.
  • Klett, J., Staats, D. and Salts, J. 2011. Annual Flower Trial Garden Performance Report. 184 p.
  • Klett, J., Hammond, E. and Staats, D. 2011. Perennial Flower Trial Performance Report. 30 p.
  • Smith, J. and Klett, J. 2011. Impact of Limited Irrigation on Four Common Shrub Species. Colorado Water. 28(2):2-4.
  • MacDonald, Robert. J. 2011. Woody Plant Evaluation in Colorado. M.S.Thesis, Spring 2011:54 p.
  • OConnor, A., Klett, J. and Koski, A. 2011. Nursery Tree Production and Transplant Success of Pyrus calleryana Glens Form (Chanticleer) Influenced by Container Types and Overwintering Treatment. Abstract. Hort Sci. 46(9):p. 5325.
  • Klett, J. and Smith, J. 2011. Shrub Water Study: An Evaluation of Four Landscape Shrub Subjected to Different Watering Regimes. Abstract. 2011 Conference Proceedings, International Society of Arboriculture, 87th Annual Conference, Sydney, Australia.
  • Klett, J. and Cummins, A. 2011. Sustainable Landscaping. CSU Extension Fact Sheet No. 7.243.
  • Klett, J. and Ford, R. 2011. Hedges. CSU Extension Fact Sheet No. 7208.
  • Bousselot, J., Klett, J., and Koski, R. 2011. Moisture Content of Extensive Green Roof Substrate and Growth Response of 15 Temperate Plant Species During Dry Down, HortScience. 46(3):518-522. Klett, J. 2011. 2010 Annual Flower Winners. CSU Research Update, Colorado Green. 27(1):12-14.
  • Klett, J. 2011. 2010 Flower Winners. CSU Research Update, Colorado Green. 27(2):16-18.
  • Klett, J. 2011. Try These Woody Plants. CSU Research Update, Colorado Green. 27(3):14-15.
  • Klett, J. 2011. Alternatives to Overused Woody Plants. CSU Research Update, Colorado Green. 27(4):12-13.
  • Klett, J. 2011. Plant Select for 2012. CSU Research Update, Colorado Green. 27(5):10-11.
  • Klett, J. and Greeb, L. 2011. Tough and Proven Perennials for Colorado. CSU Research Update, Colorado Green. 27(6):12-13.
  • Klett, J. 2011. Multi-Site Woody Plant Trials Tracking Five Species. CSU Update. CNGA Looseleaf. 29(1):19.
  • Klett, J. 2011. 2010 Top Perennial Performers. CSU Update. CNGA Looseleaf. 29(2):20-21.
  • Koski, R. and Klett, J. 2011. Weed Control Options in Container-Grown Herbaceous Ornamentals. CSU Update. CNGA Looseleaf. 29(3):20.
  • Klett, J. and Smith, J. 2011. Impact of Limited Irrigation on Four Common Shrub Species. CSU Update. CNGA Looseleaf. 29(4):20.


Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: Woody and herbaceous plants continue to be evaluated for adaptability to the High Plains on a 30 ha site. Woody (64 taxa) and herbaceous plant (52 taxa) were acquired in 2010 for evaluation. Performance records for 3140 taxa of woody and herbaceous plants were entered into a computer system, which are available on three websites. Approximately 1100 varieties of annual flowers and 80 varieties of herbaceous perennials were evaluated in 2010. In 2010, seven plant species were recommended or introduced by Plant Select. Over 70 demonstration gardens are displaying Plant Select plants throughout Colorado. The multi-site woody plant trial continued at five locations throughout the state with 6 additional taxa planted in 2010. Four herbicides Freehand G, Gallery 75 DF, Snapshot 2.5TG and Biathlon were evaluated for weed control effectiveness and phytoxicity on fifteen herbaceous perennials with the experiment repeated twice in Fort Collins. All four herbicides were safe to use on all fifteen perennial taxa. No phytotoxicity was observed on any of the herbicide applications in 2010. The drought tolerance study was continued in 2010 evaluating four mesic woody plants. Data from field study found that as watering amounts increased with redosier dogwood, Diablo ninebark and blue artic willow overall stress, aesthetic appeal and overall size was positively effected. These three taxa all survived even with no additional water added. The field Annabelle hydrangeas performed differently. Additional water yielded larger plants but were more stressed than the other three taxa. The zero percent treatment resulted in severely stressed plants but did recover if some additional moisture was applied. In the lysimeter study, the lower water treatment resulted in plants going into dormancy earlier and smaller plants with some winter dieback observed. Flowering volume with Annabelle hydrangea at the higher water rate resulted in larger and more flowers than lower rates. Plants in the higher water rates used water at a faster rate than lower water treatments. The day after watering the 100% treatment used 4 kg of water, 50% treatment used 2 kg and 25% rate used 1 kg of water. A project determining herbaceous plant species and media suitable to support green roofs in a semi-arid area was completed. Research from winter 2009-10 found the majority of remaining species overwintered extremely well with spray/irrigation. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Specific performance results from these annual, perennial and woody plant trials help determine which new and superior annual and perennial varieties growers throughout the state and region should grow and market. A performance report for annuals (summer and winter) and perennial trials was published and sent to all cooperators and industry personnel in the state and region. Many seed and vegetatively propagated varieties including coleus, New Guinea impatiens, pennisetums, spreading petunias and rudbeckias have become important bedding plant crops in the state. Plant Select plants, which are either introductions or recommendations throughout the state and region, means marketing more profitable plants for growers and retailers throughout state and region. In 2010, over 1.5 million Plant Select plants were sold and over one million people visited the 70 plus demonstration gardens. Weed control research with container grown plants helps growers control weeds considerably cheaper than hand pulling, which ultimately lowers the cost of production which is passed out to consumers. Knowledge of exact water requirements of various mesic shrub species will provide property managers and homeowners monetary savings by ultimately conserving water use. Green roofs have been shown to manage storm water, mitigate urban heat island effect and reducing air and noise pollution along with adding esthetics to urban landscapes. Various plant species and growing media can now be recommended for green roofs in a semi arid region.

Publications

  • Klett, J. 2010. Cool Season Top Performers. CNGA Looseleaf 27 (5) 12.
  • Klett, J. 2010. 2010 Best Annuals from Colorado State University. CNGA Looseleaf, 27 (6) 19.
  • Klett, J. 2010. The True Test. Grower Talks 74 (7) 56.
  • Klett, J., Staats, D. and Crist, K. 2010. Annual Flower Trial Garden Performance Report. 184 p.
  • Klett, J. 2010. 2009-10 Cool Season Trial Performance Report. 21p.
  • Klett, J., Staats, D. and Goris, D. 2010. 2009 Perennial Trial Report. 32p.
  • Bousselot, Jennifer McGuire. 2010. Extensive Green Roofs in Colorado: Plant Species Performance, Growing Media Modifications and Species Response to Growing Media Dry Down. Ph.D. Thesis. Spring 2010. 85p.
  • Staats, D., Klett, J. 2010. Preemergence Weed Control in Container Grown Herbaceous Perennials. Hort Science 45 (8) 111.
  • Smith, J., Koski, R. and Klett, J. 2010. Impact of Four Irrigation Treatments on Four Shrub Species. Hort Science 45 (8) 29.
  • Bousselot, J., Klett, J. and Koski, R. 2010. Moisture Content of Extensive Green Roof Growing Media and Growth Response of 15 Plant Species During Dry Down. Hort Science 45 (8) 44.
  • Bousselot, J., Klett, J. and Koski, R. 2010. Two Methods of Quantifying Plant Cover for Evaluating Species for Extensive Green Roof Culture. Hort Science 45 (8) 44.
  • Bousselot, J., Klett, J. and Koski, R. 2010. Evaluating a Natural Zeolite as an Amendment for Extensive Green Roof Growing Media. Paper Presentation from the 8th North America Green Roof Conference Cities Alive! Greening Rooftops for Sustainable Communities, Vancouver, Canada, 1-3 December 2010.
  • Klett, J. and Wilson, C. 2010. Xeriscaping: Perennials and Annual Flowers. CSU Extension Fact Sheets No. 7.231
  • Bousselot, J., Klett, J., and Koski, R. 2010. Extensive Green Roof Species Evaluation Using Digital Image Analysis, HortScience, 45 (8) 1288-1292.
  • Klett, J. 2010. 2009 Annual Flower Winners. CSU Research Update, Colorado Green 26 (1) 14-16.
  • Klett, J. 2010. Woody Plants for Year-Round Interest. CSU Research Update, Colorado Green 26 (2) 10-11.
  • Klett, J. 2010. Top-performing Perennials. CSU Research Update, Colorado Green 26 (3) 10-11.
  • Klett, J. 2010. Weed Control. CSU Research Update, Colorado Green 26 (4) 14.
  • Klett, J. 2010. Cool Season Top Performers. CSU Research Update, Colorado Green 26 (5) 20-21.
  • Klett, J. 2010. Superior Perennials. CSU Research Update, Colorado Green 26 (6) 13-14.
  • Klett, J. and Staats, D. 2010. 2009 Best Annual Flower List Announced, CNGA Looseleaf 27 (1) 11.
  • Klett, J. 2010. 2009 Perennial Top Performers. CNGA Looseleaf 27 (2) 10-11.
  • Hammond, E. and Klett, J. 2010. Multisite Woody Plant Trials, CNGA Loose-leaf 27 (3) 11.
  • Smith, J. and Klett, J. 2010. Impact of Limited Irrigation on Health of Four Common Shrub Species. CNGA Looseleaf 27 (4) 12-13.


Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: Woody and herbaceous plants continue to be evaluated for adaptability to the High Plains on a 30 ha site. Woody (69 taxa) and herbaceous plant (108 taxa) were acquired in 2009 for evaluation. Performance records for 3125 taxa of woody and herbaceous plants were entered into a computer system, which are available on three websites. Approximately 1076 varieties of annual flowers and twenty-five varieties of herbaceous perennials were evaluated in 2009. In 2009, six plant species were recommended or introduced by Plant Select. Over 66 demonstration gardens are displaying Plant Select plants throughout Colorado. The multi-site woody plant trial continued at five locations throughout the state with 12 additional taxa planted in 2009. Two herbicides Freehand G (dimethenamid-p + pendimethalin) Sulfosulfuron were evaluated for weed control effectiveness and phytotoxicity on fourteen herbaceous perennials with the experiment repeated twice in Fort Collins. Freehand G was safe to use on Anemone, Clematis, Dendrathemum and Nepeta. Freehand G resulted in phytotoxic symptoms in Asclepea, Lamium, Liatris and Pennisetem at all rates. It was safe at the 1x rate but not 2x and 4x rate for Guara and Lavandula. Sulfosulfuron resulted in phytotoxic symptoms in Armeria, Clematis, Lamium and Lavendula. The drought tolerance study was continued in 2009 evaluating four mesic woody plants. Findings from study found Annabelle hydrangea and redosier dogwood prefer at least some supplemental water to reduce physiological stress; however, both can survive periods of low rainfall. Diablo ninebark and blue arctic willow perform well with low water but get larger as water amounts increase. A project determining herbaceous plant species and media suitable to support green roofs in a semi-arid area continued. Research in 2009 showed that five of six species overwintered extremely well and spray irrigation more evenly distributed water than drip irrigator due to extremely well drained media. Plant area covered varied by species but some plants decreased in size due to overwintering stress and low moisture. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Specific performance results from these annual, perennial and woody plant trials help determine which new and superior annual and perennial varieties growers throughout the state and region should grow and market. A performance report for both annual and perennial trials was published and sent to all cooperators and industry personnel in the state and region. Many new seed and vegetatively propagated varieties including bacopa, coleus, gomphrena, New Guinea impatiens, and spreading petunias have become very important bedding plant crops in the state. Plant Select plants, which are either introductions or recommendations throughout the state and region, means marketing more profitable plants for growers and retailers throughout state and region. In 2009, over 1.5 million Plant Select plants were sold, over 314,000 hits on the website and over 1.3 million people visited 41 demonstration gardens. Weed control research with container plants helps growers control weeds considerably cheaper than hand pulling, which ultimately lowers the cost of production which is passed out to consumers. Knowing water requirements of various mesic shrub species will help all property managers and homeowners by ultimately conserving water use. Green Roofs manage storm water, mitigate urban heat island effect and in reducing air and noise pollution and add esthetics to urban landscapes. Plant species besides sedums can now be recommended for green roofs in a semi arid region.

Publications

  • Klett, J.E. 2009. Top Perennials. CSU Research Update, Colorado Green 25 (6) 16-17.
  • Klett, J.E. 2009. CSU Update 2008 Perennial Top Performers. CNGA Loose-leaf 26 (1) 10-11.
  • Bousselot, J.M., Klett, J.E., and R.D. Koski. 2009. High Elevation Semi-Arid Taxa: Evaluations on an Extensive Green Roof. Proc. of 7th North American Green Roof Conference. Greening Rooftops for Sustainable Communities. Atlanta, GA 3-5 June 2009. The Cardinal Group, Toronto. 10p.
  • Klett, J.E. 2009. 2008 Annual Flower Winners. CSU Research Update, Colorado Green 25 (1) 18-21.
  • Klett, J.E. 2009. Top perennials. CSU Research Update, Colorado Green 25 (2) 18-19.
  • Klett, J.E. and Smith, Jason and Koski, Ronda. 2009. High Performing, low water shrubs. CSU Research Update, Colorado Green 25 (3) 14-15.
  • Klett, J.E. 2009. All Season Woody Plants. CSU Research Update, Colorado Green 25 (4) 14-15.
  • Klett, J.E. 2009. Plant Select for 2010. CSU Research Update, Colorado Green 25 (5) 16-17.
  • Smith, Jason, Klett, J.E. and Koski, Ronda 2009. Shrub Water Study Research at Colorado State University. CNGA Loose-leaf 26 (2) 10-11.
  • Klett, J.E. 2009. More Unusual Woody Plants from Research Plots. CNGA Loose-leaf 26 (3) 17.
  • Klett, J.E. 2009. Multi-site Woody Plant Trials. CNGA Loose-leaf 26 (4) 14.
  • Klett, J.E. 2009. Plant Select Announces 2010 Selections. CNGA Loose-leaf 26 (5) 10.
  • Bousselot, Jennifer and Klett, J.E. 2009. Green Roofs in Colorado. 26 (6) 18.
  • Klett, J.E. 2009. Taking the Field. Greenhouse Grower 27 (13) 72.
  • Klett, J.E. Staats, David, Goris, Danielle. 2009. Annual Flower Trial Garden Performance Report. 173.
  • Klett, J.E. and Staats, David 2009. Preemergence Weed Control in Container Grown Herbaceous Perennials. Hort Science 44 (4) 1098.
  • Bousselot, Jennifer, Klett, J.E. and Koski, Ronda 2009. Extensive Green Roof Species and Soiless Media Evaluations in Semi-Arid Colorado. Hort Science 44 (4) 1063.
  • Koski, Ronda, Klett, J.E. and Smith, Jason 2009. Impact of Four Irrigation Treatments on Seven Shrub Species. Hort Science 44 (4) 1159.
  • Klett, J.E. and others. 2009. Durable Plants for Garden A Plant Select Guide, Plant Select. Colorado State University, Denver Botanic Gardens and Green Industries of Colorado. Edited James E. Henrich, Fulcrum Publishing. 209p.
  • Litus Gregory 2009. Drought Stress and Recovery in Green Ash. Ph.D. Thesis. Summer 2009. 95p.
  • Klett, J.E. and Wilson, C.R. 2009. Xeriscaping Ground Cover Plants. CSU Extension Fact Sheet No. 7.230.
  • Klett, J.E. and Wilson, C.R. 2009. Xeriscaping Trees and Shrubs. CSU Extension Fact Sheet No. 7.229.


Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: 4) Woody and herbaceous plants continue to be evaluated for adaptability to the High Plains on a 30 ha site. Woody (80 taxa) and herbaceous plants (63 taxa) were acquired in 2008 for evaluation. Performance records for 3,154 taxa of woody and herbaceous plants were entered into a computer system, which are available on three websites. Over 1,200 varieties of annual flowers were grown and evaluated in 2008. In 2008, seven plant species were recommended or introduced by Plant Select. Over ninety demonstration gardens are displaying Plant Select plants throughout Colorado. The multi-site woody plant trial continued at five locations throughout the state. In 2008, seven additional Plant Select plants are being recommended or introduced. Four herbicides: Mesotrione, Dinnethenaid, Flumioxazen, and Dimethenamid plus Pendimethalin were evaluated for weed control effectiveness and phytotoxicity on three landscape plants with the experiment repeated twice in Fort Collins. In this study dimethenamid showed no phytotoxicity with clematis and potentilla at recommended rate. It should only be used on Nepeta after it is established. Flumioxazen and Dimethenamid plus Pendimethalin were safe to use on all species tested at recommended rate. Mesotrione was not acceptable due to phytotoxicity for clematis and potentilla and only marginal for Nepeta. The drought tolerance study was continued in 2008 and four more mesic woody plants species were added. Additional data was recorded on common lilac, three-leaf sumac and serviceberry. Findings from study found all three species are suitable for planting in areas with limited water availability after established. A project determining herbaceous plant species and media suitable to support green roofs in a semi-arid area continued. Research in 2008 showed several native plants performed very well on green roofs, adding a soil amendment (Zeolite) increased water and nutrient holding capacity of media and was beneficial to plant growth. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Specific performance results from annual herbaceous and woody plant trials help determine which new and superior annual flowers and herbaceous perennial varieties growers throughout the state and region should be grown and marketed. A performance report was published and sent to all cooperators and industry personnel in the state and region. Many vegetatively propagated varieties including calibrachoa, coleus, geranium, New Guinea impatiens, petunia, and verbena have become very important bedding plant crops in the state, due to this research. Plant Select plants which are either introductions or recommendations throughout the state and region means marketing more profitable plants for growers and retailers throughout the state and region. In 2008, over 1.8 million Plant Select labels were sold. Weed control research with container grown plants helps growers control weeds often considerably cheaper than hand pulling, which ultimately lowers the cost of production which is often passed on to consumers. Determining water requirements of various shrub species will help all property managers and homeowners by ultimately conserving water use. Green Roofs manage storm-water, mitigate urban heat island effect, aid in reducing air and noise pollution and add beauty to the urban landscape. Plant species adaptable to green roofs in a semi-arid region are being recommended from this research.

Publications

  • Klett, J. E. 2008. CSU Update Best of 2008 Annual Flower Trials. CNGA Looseleaf 25(6) 10-11.
  • Klett, J. E. 2008. Field Tested Growers Talk. 72 (6) 60-64.
  • Klett, J. E. Staats, D. and Austin B.2008. Annual Flower Trial Gardens Performance Report. 201. Abstracts Staats, David and Klett, J.E. Preemergence Weed Control in Container-Grown Herbaceous Perennials. Hort Science 43(4) 1282.
  • Klett, J. E. 2009 and others. Durable Plants for the Garden-A Plant Select Guide, Plant Select. Colorado State University, Denver Botanic Gardens and Green Industries of Colorado-Edited James E. Henrick, Fulcrum Publishing. 209 p.
  • Klett, J. E., Staats, D., Howlett, T., and Rogoyski, M. 2008. Weed Control and Phytotoxicity Following Pre-emergence Herbicide Applications to Container-grown Herbaceous Plants. J. Environ. Hort. 26(1) 39-44.
  • Klett, J. E. 2008. 2007 Superior Annuals. CSU Research Update, Colorado Green 24(1) 56-58.
  • Klett, J. E. 2008. Perennial Trails Yield Promising Picks. CSU Research Update, Colorado Green 24(2) 62-63.
  • Klett, J. E. 2008. Woody Plants for Multi-Season Color. CSU Research Update, Colorado Green 24(3) 20-21.
  • Bousselot, Jennifer and Klett, J. E. 2008. How Do You Grow A Roof CSU Research Update, Colorado Green 24(4) 14-15.
  • Bousselot, Jennifer and Klett, J. E. 2008. Up on the Roof. CSU Research Update, Colorado Green 24(5) 18-19.
  • Klett, J. E. 2008. Plant Select for 2009. CSU Research Update, Colorado Green 24(6) 16-17.
  • Klett, J. E. 2008. CSU Update Think Tank. CNGA Looseleaf Vol 25(1) 3.
  • Klett, J. E. and Staats, D 2008. CSU Update Container Weed Control Research. CNGA Looseleaf 25(2) 10-11.
  • Bousselot, Jennifer and Klett, J. E. 2008. CSU Update Green Roof Research.CNGA Looseleaf 25(3) 12-13.
  • Klett, J. E. 2008. CSU Update More Unusual Woody Plants From Research Plots. CNGA Looseleaf 25(4) 12-13.
  • Klett, J. E. 2008. CSU Update Plant Select for 2009. CNGA Looseleaf 25(5) 9-10.


Progress 01/01/07 to 12/31/07

Outputs
Woody and herbaceous plants continue to be evaluated for adaptability to the High Plains on a 30 ha site. Woody (95 taxa) and herbaceous plants (82 taxa) were acquired in 2007 for evaluation. Performance records for 3,300 taxa of woody and herbaceous plants were entered into a computer system, which are available on three websites. Over 1,150 varieties of annual flowers were grown and evaluated in 2007 and a performance report was published and sent to all cooperators and industry personnel in the state and region. Many vegetatively propagated annual varieties including argyranthemum, calibrachoa, coleus, geranium, New Guinea impatiens, osteospermum, petunia, and verbena have become very important bedding plant crops in the state, due to this research. In 2007, seven plant species were recommended or introduced by Plant Select(registered trademark). In 2007, over 1.5 million Plant Select(registered trademark) labels were sold which is our best estimate of the number of Plant Select(registered trademark) plants sold. Over eighty demonstration gardens are displaying Plant Select(registered trademark) plants throughout Colorado. The multi-site woody plant trial continued at five locations throughout the state. Plants tested for five years are being evaluated and Cupressus arizonica from the 2002 planting will be a future Plant Select(registered trademark) recommendation. In 2008, seven additional plants are being recommended or introduced. Four herbicides: Mesotrione, Dinnethenamid, Sulfentrazone, and Dimethenamid Plus were evaluated for weed control effectiveness and phytotoxicity on six herbaceous plants with the experiment starting at three different times in Fort Collins. Sulfentrazone resulted in phytotoxicity, reduced dry weights, and some death with Echinacea purpurea. The drought tolerance study was continued in 2007 with extensive data taken on common lilac, three-leaf sumac, serviceberry, tall fescue, and Kentucky bluegrass. The tall fescue and Kentucky bluegrass showed physiological stress due to water. The shrub species with more extensive rooting systems only showed some minor stress at lower water treatments. A project determining herbaceous plant species and media type suitable to support green roofs in a semi-arid, high elevation area was initiated in 2007.

Impacts
Specific performance results from annual herbaceous and woody plant trials help determine which new and superior annual flowers and herbaceous perennial varieties growers throughout the state and region will grown and market. These superior annuals and herbaceous perennials will become available to consumers who ultimately will be more successful in gardening. Plant Select(registered trademark) plants which are introduced or recommended throughout the state and region mean marketing more profitable plants for growers in the state and region. Weed control research helps growers control weeds in container production, which ultimately lowers the cost of production which is often passed on to consumers. Water requirements of shrub and turf species will help all property managers and homeowners by ultimately conserving water use. The landscaped Green Roofs ultimately help in storm-water management, reducing Urban Heat Island Effect, and for general aesthetics. The feasibility of these in a semiarid area will be examined.

Publications

  • Klett, J. E. 2007. Plant Select(registered trademark) for 2007. ColoGreen 23(2) 64-65.
  • Klett, J. E. 2007. Superior Herbaceous Perennials. ColoGreen 23(3) 52-54.
  • Klett, J. E. 2007. Container Weed Control. ColoGreen 23(4) 48-49.
  • Klett, J. E. 2007. The Root of the Matter. ColoGreen 23(5) 54-55.
  • Klett, J. E. 2007. Plant Select(registered trademark) Update. ColoGreen 23(6) 50-51.
  • Klett, J. E., Litus, Gl., And Ounsworth, M. 2007. Woody Plant Drought Study. Looseleaf 24(1) 16.
  • Klett, J. E. 2007. 2006 Annual Winners. ColoGreen 23(1) 59-60.
  • Klett, J. E. 2007. More Unusual Woody Plants from Research Plots. Looseleaf 24(2) 10-11.
  • Ounsworth, M. and Klett, J. E. 2007. The Root of the Matter. Looseleaf 24(4) 8.
  • Klett, J. E. 2007. Superior Herbaceous Perennials from Research Plots. Looseleaf 24(3) 10-11.
  • Klett, J. E. 2007. Plant Select(registered trademark). Looseleaf 24(5) 12-13.
  • Klett, J. E. 2007 Best 2007 Annual Flower Trials. Looseleaf 24(6) 6-7.
  • Klett, J. E., Staats, D., and Brescher. 2007. Colorado State University 2007 Annual Flower Trial Garden Performance Report. 207p.
  • Klett, J. E., Staats, D., Howlett, T., and Rogoyski, M. 2008. Weed Control and Phytotoxicity Following Pre-emergence Herbicide Applications to Container-grown Herbaceous Plants. J. Environ. Hort. 26(1) 39-44.
  • Klett, J. E. and MacDonald. 2007. Multi-site Woody Plant Evaluation in Colorado. Hort. Science 42(4) 995. (Abstract)
  • Howlett, T., Staats, D., and Klett, J. E. 2007. Efficacy and Phytotoxicity of Pre-emergence Herbicides in Container-grown Landscape Plants. Hort Science 42(4) 877. (Abstract)


Progress 01/01/06 to 12/31/06

Outputs
Woody and herbaceous plants continue to be evaluated for adaptability to the High Plains on a 30 ha site. Woody (53 taxa) and herbaceous plants (22 taxa) were acquired in 2006 for evaluation. Performance records for 2950 taxa of woody and herbaceous plants were entered into a computer system, which are available on three websites. Over 1,300 varieties of annual flowers were grown and evaluated in 2006 and a performance report was published and sent to all cooperators and industry personnel in the state and region. Many vegetatively propagated annual varieties, including argyranthemum, calibrachoa, coleus, New Guinea impatiens, osteospermum, petunia and verbena have become important bedding plant crops in the state, due to this research. In 2006, eight plant species were recommended or introduced by Plant Select. In 2006, over 1.7 million Plant Select plant labels were sold which is our best estimate of the number of Plant Select plants sold. Over seventy-five demonstration gardens are displaying Plant Select plants throughout Colorado. The multi-site woody plant trial continued at five locations throughout the state with the additional planting of seven taxa in spring of 2006. Plants tested for five years are being extensively evaluated and Cupressus arizonica from the 2002 planting will be a future Plant Select recommendation. In 2007, seven additional plants are being recommended or introduced. Three herbicides: sulfentrazone, halosulfron and experimental V-10142 were evaluated for weed control effectiveness and phytotoxicity on four herbaceous plants with the experiment starting at three different times in Fort Collins. Sulfentrazone, halosulfron, and V-10142 resulted in phytotoxicity and reduced dry weights on three of four plant species evaluated. The 2006 season was a very dry season in Fort Collins which yielded exceptional data on the water use study of landscape shrubs and turfgrass. In the lysimeter study, plant water use at full saturation by plant area shows that Kentucky bluegrass uses about 65% of reference ETo. Bluemist spirea used about 60% of reference ETo. Both common lilac and three-leaf sumac used less water than Kentucky bluegrass. In the drought tolerance study, visual ratings showed tall fescue and Kentucky bluegrass were the only plant species to show physiological stress due to water. Depth of rooting is a common drought avoidance mechanism. This is one major difference between shrub and grass species. More extensive rooting systems result in more water available to plants. Irrigation in the landscape should focus less on individual plant's water use and more on maintaining adequate soil moisture in plant rooting zone.

Impacts
Specific performance results from annual flower trials will help determine which new and superior annual flower varieties growers throughout state and region will grow and market. These superior annuals will become available to consumers who ultimately will be more successful in gardening. Plant Select plants which are introduced or recommended throughout the state and region mean marketing more profitable plants for growers in the state and region. Weed control research helps growers control weeds in container production, which ultimately lowers overall cost of production, which is often passed on to consumers. Water requirements of shrub and turf species will help all property managers and homeowners ultimately conserve water use in landscapes.

Publications

  • Klett, J.E. 2006. Superior Annuals. Colo Green 22 (1) 52-54.
  • Klett, J.E. 2006. Unusual Woody Plants. Colo Green 22 (2) 61-62.
  • Klett, J. E. 2006. Underused Woody Plants. Colo Green 22 (3) 61-62.
  • Klett, J.E. 2006. Proven Herbaceous Perennials. Colo Green 22 (4) 61-62.
  • Klett, J.E. and MacDonald, R. 2006. Plant Select Woody Plant Trials. Colo Green 22 (5) 61-62.
  • Klett, J.E. 2006. More Unusual Woody Plants from Research Plots. Looseleaf 23 (1) 18.
  • Ounsworth, M. and Klett, J.E. 2006. Water Requirements of Landscape Shrubs and Turfgrass. Looseleaf 23 (2) 8.
  • Klett, J.E. 2006. Plant Select for 2007. Looseleaf 23 (4) 12-13.
  • Ounsworth, M. and Klett, J.E. 2006. Drought Avoidance and Drought Tolerance. Looseleaf 23 (5) 12-13.
  • Klett, J.E. 2006. Superior Annuals from the 2006 Trials. Looseleaf 23 (6) 12-13.
  • Klett, J.E., Copenhefer, C. and Staats, D. 2006. Colorado State University 2006 Annual Flower Trial Garden Performance Report 123 p. (unpubl.)
  • Klett, J.E. 2006 Colorado State University 2005-06 Winter Pansy Trials Performance Report (unpubl.)
  • Klett, J.E. and Cox, R.A. 2006. Evergreen Shrubs for the Home Grounds. Colorado State University Coop. Ext. Gardening Series. No. 7.414. 6 p.
  • Klett, J.E. 2006. Butterfly Bloom. 25 North, May/June 2005. p. 54.
  • Litus, G. and Klett, J.E. 2006. Drought Stress and Recovery in Green Ash. HortScience 41 (4) 1009 (Abstract.
  • Staats, D., Klett, J., Howlett, T. and Rogoyski, M. 2006. Pre-emergence Weed Control in Container-grown Herbaceous Perennials. HortScience 41 (4) 1034 (Abstract)


Progress 01/01/05 to 12/31/05

Outputs
Woody and herbaceous plants continue to be evaluated for adaptability to the High Plains on a 30 ha site. Woody (55 taxa) and herbaceous plants (160 taxa) were acquired in 2005 for evaluation. Performance records for 2975 taxa of woody and herbaceous plants were entered into a computer system, which is available on three websites. Over 1,150 varieties of annual flowers were grown and evaluated in 2005 and a performance report was published and sent to all cooperators and industry personnel in the state and region. Many vegetatively propagated annual varieties, including petunias, calibrachoa, verbenas, osteospermums and New Guinea impatiens have become important bedding plant crops in the state, due to this research. In 2005, seven plant species were recommended or introduced by Plant Select. In 2006, eight additional plants are being recommended or introduced. In 2005, over 1.3 million Plant Select plant labels were sold which is our best estimate of the number of Plant Select plants sold. Over fifty-five demonstration gardens are displaying Plant Select plants throughout Colorado. The multi-site woody plant trial continued at five locations throughout the site along with a cold hardiness study conducted with Cupressus arizonica at three of the sites. Three herbicides: Pendulum 2G (pendimethalin), Pennant Magnum 26EC (s-metolachlor) and Snapshot 2.5+G (isoxabem + trifuratin) were evaluated for weed control effectiveness and phytotoxic effect on four genera of herbaceous plants at two sites in Colorado. Pennant Magnum 7.26EC resulted in severe phytotoxicity and stunted growth at most rates on all four taxa. Snapshot 2.5+G at recommended rate resulted in no phytotoxicities or stunted growth. The safest herbicide applied was Pendulum 2G which resulted in no phytoxicity and good weed control. In 2005 research began on determining water requirements of eight landscape shrubs and two species of turf grass. The 2005 season was used to design the research area, install the irrigation system and plants and various data collection techniques. The pot-in-pot method is being used to gravimetrically determine plant water loss. Baseline data was acquired in 2005 in this study and a drought tolerance study with plants being subjected to four different amounts of supplemental irrigation (100%, 50%, 25% and 0% of ET) was established. Research continues on determining water use in a multi-canopy urban landscape with Fraxinus pennsylvanica. The plots are exposed to varying levels of irrigation and are monitored to measure soil water depletion. Stem flow gauges are being used to measure water uptake. Stomatal conductance, water potential and leaf temperatures are being measured in the trees in various plots.

Impacts
Specific performance results from annual flower trials will help determine which new and superior annual varieties growers throughout state and region will grow and market. These superior annuals will be available to consumers who ultimately will be more successful in gardening. Plant Select plants which are introduced or recommended throughout the state and region means marketing more profitable plants for growers in the region. Weed control research helps growers control weeds in container production, which ultimately lowers the overall cost of production, which is often passed on to consumers. Exact water requirements of shrub species will help all property managers and homeowners ultimately conserve water use in landscapes.

Publications

  • Klett, J.E. 2005. Current Nursery and Greenhouse Research Projects. Looseleaf 22(1) 5.
  • Klett, J.E. 2005. Research Continues Evaluating Herbaceous Perennials Best Suited for Region. Looseleaf 22(2) 8, 14.
  • Klett, J.E. 2005. Research Update, Thoughts from the Think Tank. Looseleaf 22(3)14.
  • Klett, J.E. 2005. Plant Select Update. Looseleaf 22(4) 19.
  • Klett, J.E. 2005. Superior Annuals from 2005 Trials. Looseleaf 22(5) 9, 10.
  • Klett, J.E. 2005. Container Weed Control Research. Looseleaf 22(6) 4.
  • Klett, J.E. 2005. Standing Trial. Growers Talk 9(6) 64.
  • Klett, J.E. 2005. Trialing the New Varieties. Greenhouse Product News 15(13) 60.
  • Klett, J.E, Copenhefer, C. and Staats, D. 2005. Colorado State University 2005 Annual Flower Trial Garden Performance Report . 95 p. (unpub.)
  • Klett, J.E. 2005. Colorado State University 2004-05 Winter Pansy Trials Performance Report. 28 p. (unpub.)
  • Klett, J.E. and Cox, R.A.. 2005. Rock Garden Plants. Colorado State University Coop. Ext. Gardening Series No. 7.401. 4p.
  • Cox, R.A. and Klett, J.E.. 2005. Evergreen Trees. Colorado State University Coop. Ext. Gardening Series No. 7.403. 4p.
  • Klett, J.E., Staats, D. and Rogoyski, M. 2005. Pre-emergence Weed Control in Container-grown Herbaceous Perennials. HortScience 40(4) 1024. (abstract)
  • Hughes, H., Mogen, E., Newman, S., Klett, J. and Koski, A. 2005. Outcome Assessment of Resident Instruction: The Colorado State University Experience. HortScience 40(4) 1045. (abstract)
  • Litus, G. and Klett, J.E. 2005. Comparison of First and Second-Year Growth between Container-grown Autumn Blaze Maple Trees. HortScience 40(4) 1125. (Abstract)
  • Qian, Y. L., Fu, J. M., Klett, J.E. and Newman, S.E. 2005. Effects of Long-Term Recycled Wastewater Irrigation on Visual Quality and Ion Concentrations of Ponderosa Pine. J. Environ. Hort. 23(4) 185-189.
  • Klett, J. E. 2005. Superior Annuals. ColoGreen 21(1) 64.
  • Klett, J.E. 2005. Container vs B&B for Woody Plants. ColoGreen 21(2) 58-59.
  • Klett, J.E. 2005. 2005 Research Project. ColoGreen 21(3) 53-54.
  • Klett, J.E. 2005. Planttalk Colorado Keeps on Growing. ColoGreen 21(4) 53.
  • Klett, J. E. 2005. Planttalk Colorado. 24-Hour Answer for Gardeners. HortScience 40(4) 995. (Abstract)


Progress 01/01/04 to 12/31/04

Outputs
Woody and herbaceous plants continue to be evaluated for adaptability to the High Plains on a 25 ha site. Woody (76 taxa) and herbaceous plants (140 taxa) were acquired in 2004 for evaluation. Performance records for 2850 taxa of woody and herbaceous plants were entered into a computer system, which are available on two websites. Close to 1,000 varieties of annual flowers were grown and evaluated in 2004 and a performance report was published and sent to all cooperators and industry personnel in the state and region. Many vegetatively propagated annual varieties, including petunias, verbenas and New Guinea impatiens have become important bedding plant crops in the state, due to this research. Seven plant species were recommended or introduced to the trade and public by Plant Select in 2004. In 2005, seven additional plants are being recommended or introduced. In 2004, close to one million Plant Select plant labels were sold which is the best estimate of the number of Plant Select plants sold. The multi-site woody plant trial continued with the planting of an additional five taxa at five locations throughout the state. A new herbicide, Pendimethalin (Pendulum 2G) was evaluated for weed control effectiveness and phytotoxic effect on twelve genera of container grown landscape plants at two sites in Colorado. The herbicide showed no phytotoxicity at either site. Pendimethalin controlled between seventy to ninety-five percent of six genera of weeds sown initially in the containers. Research continued with Acer x freemanii Autumn Blaze the second growing season to determine if container grown transplanted trees will initially grow more than ball and burlapped transplanted trees. Also, we hoped to determine if trees grown a second year in a pot-in-pot system would achieve increased growth when transplanted into larger containers. When Autumn Blaze (TM) maples are planted according to national guidelines, pot-in-pot container grown trees generated greater trunk and shoot growth than balled and burlapped transplanted trees during their first growing season after transplanting. One reason for this result was the greater amount of intact roots from the container grown trees versus balled and burlapped trees resulting in less water stress in the young trees. No significant differences in trunk or shoot growth were observed when pot-in-pot grown trees were transplanted to larger pot-in-pot containers versus staying in smaller pot-in-pot container after one growing season.

Impacts
Specific performance results from annual flower trials will help determine which new and superior annual varieties growers throughout state and region will grow and market. These superior annuals will be available to consumers who ultimately will have more success in gardening. Plant Select plants promoted throughout region and country mean more profitable plants to growers and ultimately gardeners. Weed control research helps growers control weeds in container production, which ultimately lowers the overall cost of production, which is often passed on to consumers.

Publications

  • Klett, J.E. 2004. Superior Annuals from 2003 Trials. ColoGreen 20 (1):51-52.
  • Klett, J.E. 2004. Plant Select Woody Plants. ColoGreen 20 (2):50-51.
  • Klett, J.E. and MacDonald, R. 2004. Woody Plants. ColoGreen 20 (3):41-42.
  • Klett, J.E. 2004. Superior Herbaceous Perennials. ColoGreen 20 (4):50-52.
  • Klett, J.E., Cosenza, J. and Staats, D. 2004. Colorado State University 2004 Annual Trial Garden Performance Report. 95 p. (unpub.)
  • Klett, J.E. 2004. Research Update. Looseleaf 21 (1):13.
  • Klett, J.E. and Litus, G. 2004. Water Use in Autumn Blaze Maple. Looseleaf 21 (2):6.
  • Klett, J.E. 2004. Thoughts from Think Tank Meeting. Looseleaf 21 (3):7-8.
  • Klett, J.E. and Litus, G. 2004. Water Use Studies with Woody Plants. Looseleaf 21 (5):4-5.
  • Klett, J.E. 2004. Superior Annuals from 2004 Trials. Looseleaf 21 (6):7.
  • Klett, J.E. 2004. Bedding Plant Trials. Greenhouse Product News 14(13):26.
  • Klett, J.E. 2004. Best in the Field. Grower Talks 68 (6):40-41.
  • Klett, J.E. 2004. Tried and True. Greenhouse Grower 22 (12):60.
  • Shonle, I, Vickerman, L. and Klett, J.E. 2004. Native Herbaceous Perennials for Colorado Landscapes. Colorado State University Coop. Ext. Gardening Series No. 7.242 6 p.
  • Klett, J.E., Staats, D. and Rogoyski, M. 2004. Preemergence Weed Control in Container Grown Herbaceous Perennials. HortScience 39 (4):745-46. (abstract).
  • Litus, G. 2004. The Effects of Water Limitation and Heat on Flower Production, Resource Allocation and Partial Style Abscission in Oenothera macrocarpa ssp. incana. M.S. Thesis. Department of Horticulture & Landscape Architecture. Colo State Univ. Fort Collins, CO 77 pgs.


Progress 01/01/03 to 12/31/03

Outputs
Woody and herbaceous plants continue to be evaluated for adaptability to the High Plains on a 25 ha site. Woody (85 taxa) and herbaceous plants (74 taxa) were acquired in 2003 for evaluation. Performance records for 2800 taxa of woody and herbaceous plants were entered into a computer system which is available on a website. Over 950 varieties of annual flowers were grown and evaluated in 2003 and a performance report was published and sent to all cooperators and industry personnel in the state and region. New Guinea impatiens, angelonia, vegetatively propagated petunias and verbenas have become a more important bedding plant crop in the state. Seven plant species were recommended or introduced to the trade and public by Plant Select (TM) in 2003. In 2004 seven additional plants are being recommended or introduced. In 2003 over 900,000 Plant Select (TM) plant labels were sold which is the best estimate of the number of Plant Select (TM) plants sold in 2003. The multi-site woody plant trial continued with the planting of an additional eight taxa at five locations throughout the state. A new herbicide:flumioxazin (Broadstar) was evaluated for weed control effectiveness and phytotoxic effect on twelve genera of container grown landscape plants at two sites in Colorado. Most herbicides tested controlled weeds well with phytotoxicity observed only on Cerastium tomentosum, Achillea millifolium, Hydrangea arborescens, and Lonicera tatarica at two and four times the recommended rate. Phenotypic plasticity of Oenothera macrocarpa ssp.incana response to heat, water and light stress was studied. Only minor variations were observed in plant form in response to water and heat stress. However, a phenomenon termed partial style abscission (PSA) occurred from late June until early October. PSA occurred more frequently with increasing daily temperatures and contributed to limiting seed set with 0. macrocarpa ssp. incana. Preliminary lysimeter research was initiated in 2003 to determine daily water use of Acer x freemanii 'Jeffersred'-Autumn Blaze(TM) maple during cycles of decreasing soil moisture. Future lysimeter research will focus on root development and water use.

Impacts
Improper selection of landscape plant material can result in financial loss and dissatisfaction to homeowners and industry personnel. Introduction and evaluation of adaptable landscape plant material will identify proper plant material. Container production of landscape plants continues to offer a challenge to Colorado growers. Research will continue to define safe and effective herbicides and other modified container production techniques so growers will be successful. Daily water use of container nursery crops needs to be known to help in drought years. Research will continue to determine water use for maximum growth.

Publications

  • Klett, J. E. 2003. Flowers for Color in Drought. ColoGreen 19(1):37.
  • Klett, J. E. 2003. Superior Annuals from 2003 Trials. ColoGreen 19(2):32
  • Klett, J. E. 2003. Drought and Heat Tolerance of Herbaceous Perennials. ColoGreen. 19(3):31.
  • Klett, J. E. 2003. New Trees Evaluated. ColoGreen 19(4):34.
  • Klett, J. and Mobley, R. 2003. Colo. State Univ. 2003 Annual Trial Garden Performance Report. 86 p. (Unpublished)
  • Klett, J. E. 2003. Plant Select CNA Looseleaf. 20(1):11-12
  • Klett, J. E. 2003. Best Perennials for Rocky Mountain and High Plains. CNA Looseleaf. 20(2):7
  • Klett, J. E. 2003. Woody Plant Trial Performance Report. CNA Loosleaf. 20(3):8.
  • Klett, J. and Cummins, A. 2003. Tree Production Utilizing Pot-In-Pot Techniques. CNA Loosleaf. 20(4):15.
  • Klett, J. E. 2003. Woody Plant Evaluation Report. CNA Looseleaf. 20(5):17-19.
  • Klett, J. E. 2003. 2003 Annual Flower Trial Report. CNA Looseleaf. 20(6):9.
  • Klett, J. E. 2003. Field Trial Fanfare. GM Pro. 23(10):31.
  • Klett, J. E. 2003. Summer's Best. Greenhouse Grower. 21(12):60-61.
  • Klett, J. E. 2003. 2003 Bedding Plant Trials. Greenhouse Product News. 13(13):20.
  • Klett, J. E. 2003. Dispatches from the Field. Growers Talk. 67(6):37.
  • Klett, J. E. 2003. Home Landscape Watering During Drought. Colo. State Univ. Coop. Ext. Gardening Series No. 7.240.
  • Klett, J., Staats, D. and Rogoyski, M.. 2003. Pre-emergence Weed Control in Container-grown Herbaceous Perennials and Woody Plants. HortScience 38(5):700 (abstract)
  • Klett, J. and Badertscher, K. 2003. Planttalk Colorado. HortScience. 38(5):731 (abstract)
  • Litus, G. and Klett, J. 2003. Partial Style Abscission in Oenothera macrocarpa spp. incana. HortScience 38(5): 776 (abstract)
  • Cummins, A. 2003 Tree production utilizing Pot-in-POt Techniques. M.S. Thesis. Department of Horticulture & Landscape Architecture. Colo State Univ. Fort Collins, CO 73pgs.


Progress 01/01/02 to 12/31/02

Outputs
Woody and herbaceous plants continue to be evaluated for adaptability to High Plains on a 22 ha site. Woody (70 taxa) and herbaceous plants (30 taxa) were acquired in 2002 for evaluation. Performance records for 3,212 taxa of woody and herbaceous plants were entered into a computer system. Over 1,165 varieties of annual flowers were grown and evaluated during the 2002 season and a performance report was published and sent to all cooperators and industry personnel. As a result of these trials, New Guinea Impatiens and vegetatively propagated petunias, verbena's and dahlia's have become more important flower crops in the state. Seven plant species were recommended or introduced to the trade and public by Plant Select in 2002. In 2003, seven plants are being recommended or introduced. In 2002, a multi-site woody plant trial was initiated to evaluate long term (5 years) future woody Plant Select introductions. Twelve taxa were planted at all sites. New and standard herbicides, prodiamine, trifluran, flumioxazin, isoxaben and pendimethalin were evaluated for their weed control effectiveness and phytotoxic effect on four genera of container-grown herbaceous perennials at two sites in Colorado. All herbicides tested controlled weeds well with no major phytotoxicity. In 2002, a drought and heat tolerance study with Oenothera macrocarpa ssp. Incana Silver Blade was initiated. This plant can survive and flower in dry soils. Continuous blooming in drought is credited to style abscission versus flower abscission. The multi-year feasibility study for pot-in-pot production for caliper trees continued at 2 sites. Plants at the Grand Junction site were approximately three times the size of the plants grown at the Front Range site. This is attributed to longer growing season when adequate moisture is applied. However soil temperatures remained similar between above and below ground pots throughout the year.

Impacts
Bedding plant growers and consumers throughout Colorado and the region look to Colorado State for evaluation of both seed and asexually propagated bedding plant varieties. In 2002, with more of the trials moved to a new site including container trials has increased visibility and impact of the trials to industry and public. Production and sales of New Guinea impatiens, asexually propagated verbena's, petunias and dahlia's, continue to increase due to favorable trials at Colorado State. Plant Select plants are being grown and displayed in numerous (25+) gardens throughout Colorado and the region and are displayed prominently in most garden centers. More than 510,000 Plant Select plants were tagged and sold in 2002. Herbaceous perennial growers are utilizing herbicides tested in our research plots for container production with little phytotoxicity and good weed control, saving producers dollars and labor.

Publications

  • Tannehill, C. and Klett, J.E. 2002. Best perennials for the Rocky Mountain and high plains. Colo. State Univ. Coop. Ext. Bul 573A. 128p.
  • Klett, J.E. 2002. Superior annuals. Colo. Green 18(1):31-33.
  • Klett, J.E. 2002. Superior Acer, Prunus, and Cotinus. Colo. Green 18(2):44.
  • Klett, J.E. 2002. Superior herbaceous perennials. Colo. Green 18(3):31.
  • Klett, J.E. 2002. Plant Select Xeriscape demonstration gardens. Colo. Green 18(4):31.
  • Klett, J.E. and Monroe, P. J. 2002. Colorado State University 2002 Annual trial garden performance report. 134 p. (unpublished).
  • Klett, J.E. 2002. Increasing tree quality in pot-in-pot (PIP) grown nursery stock. CNA looseleaf 19(1):6-7.
  • Klett, J.E. 2002. Field mycorrhizae research. CNA looseleaf 19(2):6.
  • Klett, J.E. 2002. Thoughts from second think tank meeting. CNA looseleaf 19(3):9.
  • Klett, J.E. 2002. Adaptability evaluation continues. CNA looseleaf 19(4):16.
  • Klett, J.E. 2002. Flower garden trials. CNA looseleaf 19(5):8-9.
  • Klett, J.E. 2002. 2002 Bedding plant trials. Greenhouse Product News. 12(13):30.
  • Klett, J.E. 2002. Passing the test. Greenhouse Grower. 20(12):38-42.
  • Klett, J.E. 2002. Field tested and approved. Grower Talks. 66(7):84.
  • Klett, J.E., Fahey, B., and Cox, R. 2002. Native trees for Colorado landscapes. Colo. State Univ. Coop. Ext. Gardening Series. No. 7.421.
  • Klett, J.E., Fahey, B., and Cox, R. 2002. Native shrubs for Colorado landscapes. Colo. State Univ. Coop. Ext. Gardening Series. No. 7.422.
  • Staats, D. and Klett, J. 2002. Pre-emergence weed control in container-grown herbaceous perennials. XXVI International Horticultural Congress. Toronto, Ontario. P. 615 (abstr).
  • Cummins, A., Klett, J. and Rogoyski, M. 2002. Tree production utilizing Pot-in-Pot techniques. XXVI International Horticultural Congress. Toronto, Ontario. P. 464 (abstr).


Progress 01/01/01 to 12/31/01

Outputs
Woody and herbaceous plants continue to be evaluated for adaptability to High Plains on a 22 ha site. Woody (55 taxa) and herbaceous plants (28 taxa) were acquired in 2001 for evaluation. Performance records for 3,023 taxa of woody and herbaceous plants were entered into a computer system. Crabapples (90 clones) continue to be evaluated for fireblight resistance and landscape features. Over 1,100 varieties of annual flowers were grown and evaluated during the 2001 season and a performance report was published and sent to all cooperators and industry personnel. As a result of these trials, New Guinea Impatiens and vegetatively propagated Verbena's have become a more important flower crop to the state. Seven plant species were recommended or introduced to the trade and public by Plant Select in 2001. Over 450,000 of the 2001 Plant Select plants were tagged or sold in 2001. In 2002, seven plants are being recommended or introduced. New and standard herbicides, Oxyfluorfen and pendimethalin, benefin and trifluralin, oxadiazon, oxyfluorfen and oryzalin and pendimethalin were evaluated for their weed control effectiveness and phytotoxic effect on six genera of container-grown herbaceous perennials and woody plants at two sites in Colorado. All herbicides tested controlled weeds well with no major phytotoxicity. A multi-year study was started in 2001 at two sites in Colorado to study the feasibility of pot-in-pot production system for caliber tree production. Initial data after one growing season shows some increased growth from this system with additional fertilizer and water treatments. Another cooperative multi-year study was initiated in 2001 to determine the importance of mycorrhizae treatments to newly transplanted and established trees in the landscape. Initial results after one growing season has not resulted in any significant increase in growth due to various mycorrhizal treatments.

Impacts
Bedding plant growers and consumers throughout Colorado and the region look to Colorado State for evaluation of both seed and asexually propagated bedding plant varieties. In 2001, with the partial move of the trials to a new site has increased visibility and impact of the trials to industry and public. Production and sales of New Guinea impatiens, geraniums and asexually propagated verbena and petunia continue to grow, due to favorable trials at Colorado State. Plant Select plants are being grown and displayed in numerous (20+) gardens throughout Colorado and the region and are displayed prominently in most garden centers. More than 450,000 Plant Select plants were tagged and sold in 2001. Nursery and herbaceous plant growers are utilizing numerous herbicides tested in our research plots for container production with little phytotoxicity and good weed control, saving producers dollars and labor.

Publications

  • Staats, D. and J. Klett. 2001. Preemergence Weed Control in Container-Grown Herbaceous Perennials. HortScience 36(3):500 (abstr.)
  • Klett, J.E., H. McMillan and S. Eubank. 2001. Planttalk Colorado . HortScience 36(3):478 (abstr.)
  • Klett, J.E. and C. Sikora. 2001. Colorado State University 2001 Annual Trial Garden Performance Report. 178 p. (Unpubl.)
  • Boyles, M. and J.E. Klett. 2001. Superior Annuals from 2000 Trials. Colo. Green. 17(1):35-38.
  • Klett, J.E. 2001. Fertilizer for Container-Grown Annuals. Colo. Green. 17(2):30-37.
  • Klett, J.E. 2001. Proven Herbaceous Perennials. Colo. Green. 17(3):20-25.
  • Klett, J.E. 2001. Promising Woody Plants for 2002. Colo. Green. 17(4):37-38.
  • Klett, J.E. 2001. Plenty O'Plants. Amer. Nurseryman 194(12):36, 62, 63, 68.
  • Klett, J.E. 2001. Outstanding in the Field. Growers Talk 65(6):38-42.
  • Klett, J.E. 2001. Summer's Best. Greenhouse Grower. 19(12):44-45.
  • Klett, J.E. 2001. Plant Select Woody Plant Selections for 2001 and 2002. CNA Looseleaf 18(3):12-13.
  • Klett, J.E. 2001 Research Think Tank Held. CNA Looseleaf 18(4):6.
  • Klett, J.E. 2001. 2001 Annual Flower Garden Trials. CNA Looseleaf. 18(5):6.


Progress 01/01/00 to 12/31/00

Outputs
Woody and herbaceous plants continue to be evaluated for adaptability to High Plains on a 22 ha site. Woody (86 taxa) and herbaceous plants (84 taxa) were acquired in 2000 for evaluation. Performance records for 2,787 taxa of woody and herbaceous plants were entered into a computer program. Crabapples (90 clones) continue to be evaluated for fireblight resistance and landscape features. Over 950 varieties of annual flowers were grown and evaluated during the 2000 season and a performance report was published and sent to all cooperators and industry personnel. As a result of these trials, New Guinea Impatiens have become a more important annual flower crop in the state. Five plant species were recommended or introduced to the trade and public by Plant Select in 2000. Over 175,000 of the 2000 Plant Select plants were tagged or sold in 2000. In 2001, seven plants are being recommended or introduced. Chrysothamnus (8 sources) continue to be field evaluated for growth habit and foliage color. New and standard herbicides, oryzalin, oxadiazon, oxyfluorfen + oryzalin, oxyfluorfen + pendimethalin, benefin and trifluralin, prodiamine, and pendimethalin were evaluated for their weed control effectiveness and phytotoxic effect on six genera of container-grown herbaceous perennials and woody plants. All herbicides tested controlled weeds well with no major phytotoxicity. A three-year field study started in 1997 continued to study the impact of post harvest storage methods on physiological quality and transplant success of balled and burlapped Tilia cordata `Greenspire'. After three years in the field, it appears that any initial benefits of mulching and containing root growth during storage were no longer apparent. Any stress from storage techniques prior to transplanting was not significant. Growth increments show greater growth in the third year associated with fabric treatment and no differences between other treatments.

Impacts
Bedding plant growers & consumers throughout Colorado & the region look to Colorado State for evaluation of both seed and asexually propagated bedding plant varieties. Production & sales of New Guinea impatiens, asexually propagated verbena, petunia and angelonia have grown tremendously due to favorable trials at Colorado State. Plant Select plants are now being grown and observed in gardens throughout Colorado and are available in most garden centers. These plants are hardier & more adaptable to Colorado climatic conditions. More than 175,00 Plant Select plants were tagged and sold in 2000. Nursery producers are utilizing numerous herbicides tested in our research plots for container grown herbaceous perennials with little phytotoxicity and good weed control saving producers dollars and labor.

Publications

  • Klett, J. E. 2000. Woody Plants worth considering in 2000. Colo. Green 16(2): 34-37.
  • Klett, J.E. 2000. New Plants for 2001. Amer. Nurseryman 912(12):40, 52.
  • Klett, J.E and M. Boyles. 2000. Summer's best - University trials - Colorado State. Greenhouse Grower 18(12): 94, 96, 98.
  • Klett, J. E., and D. Staats. 2000. Preemergent Weed Control in Container-Grown Herbaceous Perennials. HortScience. 35(3):221(abstr).
  • Oakley, D., J. Laufman, J. Klett, and H. Hughes. 2000. Overcoming seed dormancy in winecups, Callirhoe involucrata. HortScience 35(3):450 (abstr.).
  • Klett, J. E. and M. Boyles 2000. Colorado State University 2000 Annual Flower Trial Garden Report. 171 p. (unpub)
  • Waltman, D., J. E. Klett and R. A. Cox. 2000. Perennial gardening. Colorado State Univ. Coop. Ext. Gardening Series. No. 7.402
  • Klett, J. E. 2000. Flowering crabapples as ornamental trees. Colo. Green 16(4):35-37.
  • Klett, J.E. 2000. Ornamental grasses from Colorado State's research trials. Colo. Green 16(3):34-35.
  • Klett, J. E. 2000. Annuals for the new millennium. Colo. Green. 16(1):38-41.


Progress 01/01/99 to 12/31/99

Outputs
Woody and herbaceous plants continue to be evaluated for adaptability to High Plains on a 22 ha site. Woody (55 taxa) and herbaceous plants (137 taxa) were acquired in1999 for evaluation. Performance records for 2,702 taxa of woody and herbaceous plants were entered into a computer program. Over 787 varieties of annual flowers were grown and evaluated during the 1999 season and a performance report was published and sent to all cooperators and industry personnel. Acer grandidentatum seedlings (3 sources) were distributed to 27 sites for regional evaluation and third-year evaluation reports were received and recorded. Eight plant species were recommended or introduced to the trade and public by Plant Select in 1999. Over 1.5 million Plant Select plants were tagged or sold since it started in 1997. In 2000, five plants are being recommended or introduced. Chrysothamnus (8 sources) continue to be field evaluated for growth habit and foliage color. New and standard herbicides, napropamide, oryzalin, oxadiazon, oxyfluorfen + oryzalin, oxyfluorfen + pendimethalin, trifluralin, prodiamine, and pendimethalin were evaluated for their effectiveness of weed control and phytotoxic effect of six genera of container-grown herbaceous perennials. All herbicides tested controlled weeds well with no phytotoxicity on any of the species. A three-year field study started in 1997 was continued to study the impact of post harvest storage methods on physiological quality and transplant success of balled and burlapped Tilia cordata `Greenspire'. After two seasons in the field, it appears that mulching and containing root growth during storage appears to be beneficial to transplant success. Water stressing trees in storage appears to carry over into the transplanting phase the first year after transplanting. Tree rooting into sand during storage had a negative effect on transplant recovery the first growing season; whereas, those rooting into bark mulch were not affected negatively. However, after two growing seasons in the field, all treatments had statistically equivalent annual shoot elongation.

Impacts
Production & sales of New Guinea impatiens in Colorado has grown tremendously due to favorable trials at Colorado State. Plant Select plants are now readily available in most garden centers in Colorado, allowing consumers to plant hardier & more adaptable landscape plants. By the spring of 2000, over 2,000,000 plants will have been sold since its inception in 1997. Nursery producers & retailers are storing balled & burlapped woody plants with stretch wrap around the balls since it was found to help reduce transplant shock with woody plants.

Publications

  • KLETT, JAMES E., Laurel Potts and David Staats. 1999. Preemergent Weed Control in Container-Grown Herbaceous Perennials. HortScience. 34(3)444.
  • KLETT, J. E. 1999. New Plants for 2000. American Nurseryman. 190(12)35, 62, 70.
  • KLETT, J. E. and Brian Grubb. 1999. Potting Media for Container-Grown Annuals. Colo. Green 15(3):32-33.
  • KLETT, J.E. 1999. Under-Used Woody Plants for Colorado. Colo. Green 15(3):32-33.
  • KLETT, J. E. 1999. Root-Pruned perennials and Water Stress. Colo. Green 15(4):38-39.
  • KLETT, J.E. 1999. Annuals for the New Millennium. Colo. Green 16(1)38-41.
  • GRUBB, BRIAN 1999. Post-Harvest Storage and Establishment of Balled and Burlapped Tilia cordata Mill `Greenspire' M.S. Thesis. 64 p.
  • KLETT, J. E. 1999. Best Annuals for 1999. Colo. Green 15(1):44-45.
  • KLETT, J.E. 1999. Planttalk Colorado. Colorado Forestry Association. 18(4)1.
  • KLETT, J.E. 1999. 1999 Annual Trial Garden Performance Report. 107 p.
  • SCOTT, KIRSTEN. 1999. Enhancing Germination of Fraxinus anomala. M.S. Thesis 64 p.
  • STAATS, DAVID, David Hillock, and James E. Klett. 1999. Assessing the Risk of Phytotoxicity in Container Perennials Treated with Herbicides. Greenhouse Product News, 9(6)50-54.


Progress 01/01/98 to 12/31/98

Outputs
Woody and herbaceous plants continue to be evaluated for adaptability to High Plains on a 22 ha site. Woody (91 taxa) and herbaceous plants (48 taxa) were acquired in1998 for evaluation. Crabapples (85 clones) continue to be evaluated for fireblight resistance and landscape features. Performance records for 2,544 taxa of woody and herbaceous plants were entered into a computer program. Over 730 varieties of annual flowers were grown and evaluated during the 1998 season and a performance report was published and sent to all cooperators and industry personnel. Acer grandidentatum seedlings (3 sources) were distributed to 27 sites for regional evaluation and second-year evaluation reports were received and recorded. Six plant species were recommended or introduced to the trade and public by Plant Select in 1998. Over 255,000 of these 1998 Plant Select plants were tagged or sold in 1998. In 1999, eight plants are being recommended or introduced. Chrysothamnus (8 sources) continue to be field evaluated for growth habit and foliage color. New and standard herbicides, napropamide, oryzalin, oxadiazon, oxyfluorfen + oryzalin, oxyfluorfen + pendimethalin and trifluralin were evaluated for their effectiveness of weed control and phytotoxic effect of 8 genera of container-grown herbaceous perennials. All herbicides tested controlled weeds with no phytotoxicity except on one species. Phytotoxic symptoms appeared on Phalaris arundinacea with napropamide at the 1x and 2x rates. All other treatments provided good weed control at both rates. A three-year field study started in 1997 continued to study the impact of post harvest storage methods on physiological quality and transplant success of balled and burlapped Tilia cordata `Greenspire'. After one season in the field, it appears that mulching and containing root growth during storage appears to be beneficial to transplant success. Water stressing trees in storage appears to carry over into the transplanting phase the following year. Tree rooting into sand during storage had a negative effect on transplant recovery; whereas, those rooting into bark mulch were not affected negatively.

Impacts
(N/A)

Publications

  • DUNN, S. and KLETT, J.E. 1998. Herbaceous Perennials in Drought. Colo. Green 14(4):36-37.
  • DUNN, S., KLETT, J. E. and STAATS, D. 1998. Preemergent Weed Control in Container-grown Herbaceous Perennials. HortScience. 33(3):229 (Abstr.)
  • KLETT, J. E. 1998. New Plants for 1999. American Nurseryman 188(12):50,51,63,64,74,75
  • KLETT, J.E. 1998. Celtis occidentalis - Common Hackberry. Colorado Forestry Association Newsletter 17(6):6.
  • KLETT, J. E. 1998. Much Ado about Mulches. Colo. Green 14(3):10-12,25.
  • KLETT, J.E. 1998. Ongoing Research from CSU. Colo. Green 14(3)36-37.
  • KLETT, J. E. 1998. The Best New Annuals for 1998. Colo. Green 14(2):38-39.
  • KLETT, J.E. 1998. Xeric Annuals and Perennials. Colo. Green 14(1):40-41.
  • STAATS, D., HILLOCK, D., and KLETT, J.E. 1998. Weed Control and Phytotoxicity of Preemergence Herbicides Applied to Container-grown Herbaceous Plants. Hort Technology 8(3)325-328.
  • WALDO, A. J. 1998. The Effects of Three Nursery Production Methods on Tree Growth Rates. M.S. Thesis 65 p.
  • DUNN, S. 1998. Growth After Mechanical Root Pruning of Container-grown Perennials Under Increasing Levels of Water Stress. M.S. Thesis 130 p.


Progress 01/01/97 to 12/31/97

Outputs
Woody and herbaceous plants continue to be evaluated for adaptability to High Plains on a 22 ha site. Woody (82 taxa) and herbaceous plants (194 taxa) were acquired in 1997 for evaluation. Crabapples (80 clones) continue to be evaluated for fireblight resistance and landscape features. Performance records for 2,345 taxa of woody and herbaceous plants were entered into a computer program. Over 630 varieties of annual flowers were grown and evaluated during the 1997 season and a performance report was published and sent to all cooperators and industry personnel. Acer grandidentatum seedlings (3 sources) were distributed to 27 sites for regional evaluation and first year evaluation reports were received and recorded. Five plant species were recommended or introduced to the trade and public by Plant Select in 1997. Over 160,000 of these 1997 Plant Select plants were tagged or sold in 1997. In 1998, six plants are being recommended or introduced. Chrysothamnus (8 sources) continue to be field evaluated for growth habit and foliage color. New and standard herbicides, napropamide, oryzalin, oxadiazon, oxyfluorfen + oryzalin, oxyfluorfen + pendimethalin and trifluralin were evaluated for their effectiveness of weed control and phytotoxic effect of 5 genera of container grown herbaceous perennials. All herbicides tested controlled weeds with no phytotoxicity except on one species. Phytotoxic symptoms appeared on Phalaris arundinacea with napropamide at the 1x and 2x rates. Napropamide provided poor weed control with Scabiosa at both rates. All other treatments provided good weed control at both rates. A three year field study was started to study the impact of post harvest storage methods on physiological quality and transplant success of balled and burlapped Tilia cordata `Greenspire'. After one year the shrink wrap with mulch treatment was considered the most effective during the storage phase although transplant recovery is yet to be determined. First year results of a two year field study on mechanical root pruning and water stress indicate that root pruning of container grown perennials significantly reduces current year's growth (mean widths and densities). All four species of perennials could maintain both appearance and size under limited irrigation conditions 2.54 cm/6 days (avg daily ETo = 0.85cm).

Impacts
(N/A)

Publications

  • COX, R. A. and KLETT, J. E. 1997. Deciduous Shrubs for Colorado. Colo. State Univ. Coop Ext.Gardening Series. No. 7.415 4 p.
  • DUNN, S. , STAATS, D. and KLETT, J. E. 1997. Preemergent Weed Control in Container- grown Herbaceous Perennials. HortScience. 32(3):010 (Abstr.)
  • DUNN, S. W. and KLETT, J. E. 1997. Growth After Mechanical Root Pruning of Herbaceous Perennials Under Increasing Levels of Water Stress. HortScience 32(3)684. (Abstr.)
  • HILLOCK, D. A. and KLETT, J. E. 1997. Herbaceous Perennials and Drought Stress. Colo. Green 13(2):342.
  • KLETT, J. E. 1997. The Best, New Annuals for 1997. Colo. Green 13(1):38-39.
  • KLETT, J. E. 1997. Superior Herbaceous Perennials. Colo. Green 13(3):34-35.
  • KLETT, J. E. 1997. Ornamental Grasses for Colorado. Colo. Green 13(4):28-29.
  • KLETT, J. E. 1997. New Plants for 1998. American Nurseryman 186(12):64,68,74.
  • KLETT, J. E., BOYLE, D., COX, R. A., WILSON, C., and POTTORFF, L. 1997. Colo. State Univ. Coop. Ext. XCD08 Lawn Problem Solver CD-Rom.
  • WALDO, A. J. and KLETT, J. E. 1997. The Effects of Three Nursery Production Methods on Tree Growth Rate. HortScience 32(3):681 (Abstr.)


Progress 01/01/96 to 12/30/96

Outputs
Woody & herbaceous plants continue to be evaluated for adaptability to High Plains on a 22 ha site. Woody(119 taxa) & herbaceous plants(161 taxa) were acquired in 1996 for evaluation. Crabapples(80 clones) continue to be evaluated for fireblight resistance & landscape features. Performance records for 2060 taxa of woody & herbaceous plants were entered into a computer program. Acer grandidentatum seedlings (3 sources) were distributed to 27 sites for regional evaluation. Five plant species are being endorsed or introduced to the trade & public by Plant Select for 1996-97. Chrysothamnus (8 sources) are being field evaluated for growth habit & foliage color. New & standard herbicides, napropamide, oryzalin, oxadiazon, oxyfluorfen + oryzalin, oxyfluorfen + pendimethalin and trifluralin were evaluated for their effectiveness of weed control & phytotoxic effect on 5 genera of container grown herbaceous perennials. All herbicides tested controlled weeds with no phytotoxicity except on 3 species. Phytotoxic symptoms appeared on both Penstemon & Phlox with oryzalin at the 2x rate & on Dianthus with trifluralin at the 2x rate. Irrigation treatments resulted in Aquilegia having a decline in plant growth & appearance below 50% evapotranspiration(ET). Callirhoe at 50 & 75% ET displayed acceptable growth. Gaillardia & Gypsophilia displayed acceptable growth at 25% ET. Research continues on examining post plant growth of woody plants from different production techniques under different water regimes.

Impacts
(N/A)

Publications

  • KLETT, J. E., HILLOCK, D. & STAATS, D. 1996. Preemergent Weed Control in 7Container-grown Herbaceous Perennials. HortScience. 31(4):660 (Abstr.) HUGHES, H.
  • G. & KLETT, J.E. 1996. Accommodating Change in a Diverse HorticultureCurriculum. HortScience 31(4):694 (Abstr.) TOLAN, R. & KLETT, J. E. 1996. Review of 1995 Growing Season. Colo. Green 11(4):30-31.
  • KLETT, J. E. 1996. Annual Flower Trials - What's New for 1996. Colo. Green 12(1):34-35.
  • KLETT, J. E. 1996. Plant Select for the Rocky Mountains and Plains States. Colo.Green 12(2):34-35.
  • KLETT, J. E. 1996. Observations on Woody Plant Stress. Colo. Green 12(3):42-43.
  • KLETT, J. E. 1996. Crataegus: Hawthorn. Colo. Forestry Assoc. Newsletter 15(5):12-14.
  • KLETT, J. E. 1996. 1997 Plant Select: Colorado's Best. NM Pro.16(10)16.
  • TOLAN, R. J. 1996. Fabric Containers Versus Traditional Tree Production Methods:a Post Transplant Study. M.S. Thesis. Colo. State Univ. Ft Collins 84p.
  • HILLOCK, D. A. 1996. Herbaceous Perennials & their Performance Under Increasing Levels of Drought Stress. M.S. Thesis. Colo. State Univ. Ft Collins 102p.
  • KLETT, J. & COX, R. 1996. Ground Cover Plants. Gardening Series. No. 7.400 4p. Colo. State Univ. Coop Ext Ser.


Progress 01/01/95 to 12/30/95

Outputs
Woody & herbaceous plants continue to be evaluated for adaptability to High Plains on 22 ha. Woody(94 taxa) & herbaceous plants(69 taxa) were acquired in 1995 for evaluation. Crabapples(80 clones) continue to be evaluated for fireblight resistance & landscape features. Performance records for 1826 taxa of woody & herbaceous plants were entered into a computer program. Acer grandidentatum seedlings(14 northern sources) gained size for further evaluation in 1996. Chrysothamnus(8 sources) were field planted for evaluation of growth habit & foliage color. Selections of Juglans microcarpa & Sapindus drummondii were propagated for further evaluation. New & standard herbicides, isoxaben, napropamide, oryzalin, oxadiazon, oxyfluorfen + oryzalin & trifluralin were evaluated for their effectiveness of weed control & phytotoxic effect of 5 genera of container grown herbaceous perennials. All herbicides tested controlled weeds with no phytotoxicity except on 3 species. Phytotoxic symptoms appeared on Delosperma with oxadiazon & oxyfluorfen + oryzalin; Chrysanthemum with isoxaben & Festuca with oryzalin. Wildflower weed control research initiated in 1993 showed that elimination of weeds prior to sowing is important & trifluralin suppresses weed seeds but also wildflower seed germination. Research continued to determine water requirements of herbaceous plants & examining post plant growth of woody plants from different production techniques under various water regimes.

Impacts
(N/A)

Publications


    Progress 01/01/94 to 12/30/94

    Outputs
    Woody and herbaceous plants continue to be evaluated for adaptability to High Plains on 22ha. Woody(135 taxa) and herbaceous plants(46 taxa) were acquired in 1994 for evaluation. Crabapples(75 clones) continue to be evaluated for fireblight resistance and landscape features. Performance records for 3937 taxa of woody and herbaceous plants were entered into a computer program. Acer grandidentatum seedlings (14 northern sources) were grown in number one containers for further evaluation for the Plant Select Program. Buds from the parent trees were collected in July 1994 and placed on Acer saccharum understock. Chrysothamnus (8 sources) are being grown for selection for growth habit and foliage color. New and standard herbicides, isoxaben, metolochlor, napropamide, oxyzaline, oxadiazon, oxyfluorfen + oryzalin and treflan were evaluated for their effectiveness of weed control and phytotoxic effect of 6 genera of container grown herbaceous perennials or woody plants. All herbicides controlled weeds effectively with no phytotoxicity except on two species. Phytotoxic symptoms appeared on Digitalis and Veronica with isoxaben. Wildflower weed control research initiated in 1993 showed that two treatments of post emergent herbicide prior to planting contributes to more weed free wildflower growth. Research was initiated in 1994 to determine water requirements of four herbaceous perennials and examine post-plant growth of woody plants under different water regimes.

    Impacts
    (N/A)

    Publications

    • KLETT, J. E., STAATS, D. & HILLOCK, D. 1994. Preemergent Weed Control in Container-Grown Herbaceous Perennials. HortScience 29(5):555 (Abstr.).
    • KLETT, J. E. 1994. Maple and Ash Tree Species Worth Considering for Colorado. Colo. Green. 9(4):26-27.
    • KLETT, J. E. 1994. Annual Flower Trials: What's New for 1994. Colo. Green 10(1):30-31.
    • KLETT, J. E. 1994. Application Rate Studies of Non-Turf Groundcovers. Colo. Green 10(2):24-25.
    • KLETT, J. E. 1994. Ornamental Grasses for Landscape Use. Colo. Green 10(3):28-29.
    • STAATS, D. & KLETT, J. E. 1994. Water Conservation of Non-Turf Ground Covers vs. Kentucky Bluegrass. American Nurseryman. 180(8):85-87.
    • STAATS, D. & KLETT, J. E. 1994. Water Use of Kentucky Bluegrass and Ground Covers. HORTIDEAS 11(12):142.


    Progress 01/01/93 to 12/30/93

    Outputs
    Woody and herbaceous plants continue to be evaluated for adaptability to High Plains on a 22 ha site. Woody Plants (104 taxa) and herbaceous plants (45 taxa) were acquired in 1993 for evaluation. Crabapples (75 clones) continue to be evaluated for fireblight resistance and landscape features. Performance records for 2530 taxa of woody and herbaceous plants were entered into a computer program. Acer grandidentatum seedlings from 14 northern sources were transplanted into number one containers for further evaluation for the Plant Select Program. Eight sources of Chrysothamnus were germinated for eventual selection for growth habit and foliage color. A third seed collection trip for Plant Select program was conducted in 1993 to collect Sorbus scopulina and Juglans microcarpa seed for hardiness and fall color. New and standard herbicides, isoxaben, metolachlor, napropamide, oryzalin, oxadiazon, oxyfluorfen + oryzalin and treflan were evaluated for their effectiveness of weed control and phytotoxic effect of 11 genera of container or field grown herbaceous perennials or woody plants. All herbicides tested controlled weeds effectively with no phytotoxicity except on two species. Phytotoxic symptoms appeared on Thymus pseudolanuginosus with metolachlor and isoxaben and on Syringa vulgaris with isoxaben. Research was initiated in 1993 to study wildflower weed control. Field plots were established and three methods of weed control are being examined.

    Impacts
    (N/A)

    Publications

    • STAATS, D. & KLETT, J.E. 1993. Evaluation of Weed Control and Phytotoxicity of Preemergence Herbicides Applied to Container-Grown Herbaceous and Woody Plants. J. Envir. Hort. 11(2):78-80.
    • STAATS, D. & KLETT, J.E. 1993. Water Conservation Potential of Non-Turf Ground Covers versus Kentucky Bluegrass Under Increasing Levels of Drought Stress. HortScience 28(5):536. (Abstr.).
    • FAIRCHILD, D.H. & KLETT, J.E. 1993. Woody Landscape Plants for the High Plains. Colo. State Univ. AES Tech. Bul. LTB 93-1. 109 p.
    • FAIRCHILD, D.H. & KLETT, J.E. 1993. Woody Plants Worth Considering For Colorado Landscapes. Colo. Green 8(4):6-8.
    • REEVES, S.C. & KLETT, J.E. 1993. Reducing Herbicide Leaching in Containerized Nursery Stock. Colo. Green 9(1):15.
    • STAATS, D & KLETT, J.E. 1993. Putting Water Needs To The Test. Colo. Green 9(2):6-7.
    • REEVES, S. G. 1993. Napropamide Leaching in Container Nursery Media. M. S. Thesis. Colo. State Univ. Fort Collins, 83 p.
    • KLETT, J. E. 1993. Crabapple Evaluation Studies in Colorado. MALUS 7(2):15-17.
    • KLETT, J. E. 1993. More Unusual Trees for Colorado. Colo. For. Assn. Nwsl. 11(6):6-8.
    • STAATS, D. P. 1993. Evaluation of Quality & Water Conservation Potential of Non.


    Progress 01/01/92 to 12/30/92

    Outputs
    Woody and herbaceous plants continue to be evaluated for adaptability to the High Plains on a 22 ha site. Woody Plants(112 taxa) and herbaceous plants (151 taxa) were acquired in 1992 for evaluation. Crabapples(75 cultivars) continue to be evaluated for fireblight resistance and landscape features. Performance records for 2320 taxa of woody and herbaceous plants were entered into a computer program. Acer grandidentatum seedlings from 14 northern sources were germinated and grown for Plant Select Program. A second plant exploration for Plant Select was conducted in fall of 1992 to collect seed from Chrysothamnus species for growth habit and foliage color. New and standard herbicides, isoxaben, metholachlor, napropamide, oxyzalin, oxyfluorfen plus oryzalin and trifluralin were evaluated for their effectiveness of weed control and phytotoxic effect on 5 genera of container grown herbaceous perennials. All herbicides tested controlled weeds effectively with no phytotoxicity except on 2 species. Experiments were conducted to determine the phytotoxicity, mobility and leachate concentrations of napropramide in various container nursery media. Greatest mobility and leaching was observed in a sawdust media versus a peat media which showed the least mobility. Research continued to determine the net water requirements of ground covers compared to bluegrass utilizing evapotranspiration data based upon a modified Penman equation. Two of the groundcovers tested are water savings alternatives to bluegrass.

    Impacts
    (N/A)

    Publications

    • STAATS, D. & KLETT, J. E. 1992. How Dry Am I. Colorado Green 8(2):10-11.
    • KLETT, J. E. 1992. High Plains Perennials. Colorado Green 8(3):6-7.
    • KLETT, J. E. 1992. Woody Plants Worth Trying for Colorado. Colorado Forestry Association Newsletter 10(4):16-18.
    • REEVES, S. & KLETT, J. E. 1992. Napropamide Leaching in Container Nursery Media. HortScience 27(6):602.
    • KLETT, J. E. & BACKES, K. 1992. Composted Manures Should Be Used with Caution as Container Media. Colorado Green 7(4):36-38.
    • HOOD, L. R. & KLETT, J. E. 1992. Preemergent Weed Control in Container-grown Herbaceous & Woody Plants. J. Envir. Hort. 10(1):8-11.
    • SCHNELLE, M. A. & KLETT, J. E. 1992. The Effects of Cold Storage & Dormant Shoot and/or Root Pruning on Growth of Radiant Crabapples (Malus 'Radiant'). J. Arboriculture. 18(3):136-143.
    • SCHNELLE, M. A. & KLETT, J. E. 1992. Effects of Pruning & Bark Ringing on Total Nonstructural Carbohydrates in Regrowth of Dormant Sargent Crabapple (Malus Sargentii) Seedlings. J. Arboriculture 18(4):192-196.
    • STAATS, D. & KLETT, J. E. 1992. Evaluation of Water Conservation Potential of Non-Turf Ground Covers vs. Kentucky Bluegrass Under Increasing Levels of Drought Stress. HortScience 27(6):602.
    • KLETT, J. E. 1992. 1992 Crabapple Evaluation. Colorado Green 7(1):6-8.