LSU Agricultural Center….
Ornamental Horticulture E-mail News (May 12th)
Summer Issue – Horticulture Hints
Now online at:
http://www.lsuagcenter.com/en/communications/publications/newsletters/horticulture_hints/Horticulture+Hints+Newsletter_seriespage-2.htm
Spring Issue – Nursery and Landscape Notes
May/June Issue – Louisiana Master Gardener News
Now online at:
http://www.lsuagcenter.com/en/communications/publications/newsletters/Master+Gardener/Master+Gardener+News.htm
‘Explorer’ Series Petunia Photo Gallery
Project Descriptions – Care and Maintenance Area at the Hammond Research Station
Growth Regulation of Loropetalum and Azalea with Selected Plant Growth Regulators
Labor is the largest single cost contributor in landscape business. Pruning shrubs and trees is one of the landscape maintenance tasks requiring intensive labor, especially with foundation plantings such as loropetalum and azaleas where a compact shape is highly desired. Plant growth regulators that break apical dominance and promote lateral branching can result in similar effect as hand pruning with less cost in labor. A recently available PGR for such purpose is flurprimidol. The liquid formula is registered as Topflor for nursery containers, and the granule formula is registered as Cutless for landscape use in controlling growth of trees and shrubs. However, limited information is available on its rates effective for loropetalum and azaleas, and whether it is still effective when applied above organic mulching materials. In this study, Cutless 0.33 G will be applied at three rates either before or after the application of pine straw mulch to determine the impact of flurprimidol on ‘Merlot Lace’ loropetalum and ‘Sunglow’ azalea growth. Control effects will be evaluated by plant growth index and overall aesthetic ratings. Effects will be compared to Atrimmec and hand-pruning treatments.
Ornamental Pepper Landscape Performance Evaluation
The use of ornamental peppers as bedding and garden plants has attracted renewed interests in recent years. New varieties have been introduced to meet the demand for new plant materials. Ornamental peppers have a wide range in size, shape, foliage and fruit colors because they were selected or bred for a number of characters that enhance their visual appeal and suitability for various market applications. In this trial, 36 varieties are being evaluated by horticulturists at the Hammond Research Station for their growth habit, foliage pigmentation, fruit color and mature date, and by general consumers (Master Gardeners) for their overall landscape performance under the climate condition of southern Louisiana. This trial is being coordinated with two more locations in Mississippi to determine the most reliable and novel ornamental pepper varieties for southern gardeners.
Canna Landscape Performance
A landscape trial evaluating performance and leaf roller susceptibility of 21 Canna cultivars (Black Knight, City of Portland, Cleopatra, Crimson Beauty, Dawn Pink, Firebird, King City Gold, Maudie Malcolm, Orange Beauty, President, Pretoria, Red Dazzler, Red King Humbert, Richard Wallace, Stadt Feltbach, Striped Beauty, Tropical Sunrise, Wyoming, Yellow King Humpert, Miss Oklahoma and Lenape) was initiated in 2007 at the Hammond Research Station, Hammond, LA and Burden Center, Baton Rouge, LA. Plants were planted in raised native soil beds amended with pine bark in mid-spring at both locations and grown in full sun with drip irrigation under recommended fertilization practices. Cultivars with slight susceptibility to canna leaf roller damage in Hammond were Orange Beauty, Pretoria, Red Dazzler, Striped Beauty, and Yellow King Humpert. Cultivars with slight susceptibility to canna leaf roller damage in Baton Rouge were Striped Beauty, Miss Oklahoma, King Orange Humbert, Cleopatra, Red Dazzler, Richard Wallace, Tropical Sunrise, Maudie Malcolm and Crimson Beauty. Best quality performance (overall for both locations) was Black Knight, Yellow King Humbert, Red King Humbert, Orange Beauty, Richard Wallace, Tropical Sunrise, and King City Gold. Average performance was observed for Pretoria, Dawn Pink, Cleopatra, red Dazzler, Firebird, Crimson Beauty, Lenape, and Stadt Feltbach. Poor performance was observed for Striped Beauty, Miss Oklahoma, Wyoming, Maudie Malcolm, City of Portland, Rosemond, and President. Studies will be continued in 2008 to quantify seasonal quality performance and canna leaf roller susceptibility. In addition, several more cultivars will be added.
Knock Out Rose Pruning Study
A pruning study was initiated in February 2008 and will continue through December 2009. This study is being conducted on ‘Knock Out’ rose. Pruning treatments are: (1) no pruning, (2) continuous dead-heading (e.g. twice monthly), (3) major pruning in February, and (4) major pruning in February with minor pruning in August. Individual plants are rated weekly (visual quality) and flowering each week is quantified as to whether the plant is not in flower, has minor flowering, has average flowering, or is at peak bloom. After two years, this study will lead to information on plant size as determined by different pruning treatments and flowering on a weekly basis will be determined based on how plants are pruned.
Alternative Landscape Shrub Rose Cultivars
Several roses are planted to demonstrate some potential landscape shrub roses for possible use in south Louisiana. Cultivars included are Knock Out, Nearly Wild, Katy Road White, Bengal Tiger, Home Run, and Living Easy. In addition, Carefree Celebration, Carefree Marvel and Carefree Sunshine (roses from Knock Out rose breeder Bill Radler and Conard-Pyle) are being observed for blackspot susceptibility, growth habit and flowering characteristics.
Knock Out Rose Cultivar Evaluation
A landscape performance evaluation studying Knock Out, Knock Out Pink, Blushing Knock Out, Rainbow Knock Out, Double Knock Out, and Double Pink Knock Out was initiated in February 2008 and will continued through 2009 or 2010. This study is being replicated at Burden Center in Baton Rouge. Plants are being evaluated weekly for flowering and visual quality. This will help determine the best bloomers in the Knock Out rose family and will quantify landscape performance characteristics across cultivars.
Daylily Cultivars: Cultivar Observations and Rust Susceptibility
Interest in daylilies is still strong despite rust problems over the past several years. New daylily selections and All-American daylily winners need to be evaluated in the Gulf South for landscape performance.
A landscape trial evaluating the performance of All-American daylily cultivars was initiated in 2003 at the Ornamental and Turfgrass Research and Extension Facility located at Burden Center in Baton Rouge. This planting was transferred to the Hammond Research Station in 2007. In addition, other cultivars with commercial potential are being evaluated. The All-American Daylily Selection Council has named All-American daylilies since 1994 with winners named annually since 2002. Winners are:
• Black Eyed Stella (1994)
• Lullaby Baby (1998)
• Starstruck (1998)
• Bitsy (2002)
• Judith (2002)
• Leebea Orange Crush (2002)
• Frankly Scarlet (2003)
• Plum Perfect (2003)
• Chorus Line (2004)
• Lady Lucille (2004)
• Red Volunteer (2005)
• Miss Mary Mary (2005)
• Persian Market (2006)
• Buttered Popcorn (2006)
• Lavender Vista (2007)
• Sweet Summer Valentine (2008)
New Liriope Cultivars
