University of Arkansas Plant Evaluation Program
Plants initiated in Spring 2009 (second year data):
This completes the fifteenth year of the statewide plant evaluation program. The current team of cooperators includes Dr. Jim Robbins, Dr. Jon Lindstrom and Qingfang Chen.
The three test sites are the Hope Research Center (USDA cold hardiness zone 8), Little Rock (zone 7a) and the Fayetteville Horticulture Research farm (zone 6b). As much as possible, the three test sites were prepared in a similar manner. Full sun plants were grown in row-type beds 3’ wide with a 7’ grass alley. Plant groups are planted together (i.e. trees are planted together). Trees are spaced 10’ apart, shrubs 6’ apart, and herbaceous perennials 4’ apart. The Little Rock site was planted on April 20, 2009; Fayetteville was planted on June 2, 2009; Hope planted on April 16, 2009. Irrigation at all three sites is by a drip system. Plants were fertilized and mulched after planting. Post-emergent herbicides were used at all three test sites. No disease or insect control was implemented during the first year. To maintain a tree-like habit, trees are pruned following final growth measurements. Pruning consists of removing the bottom one-third of limbs. SHRUBS are NOT pruned. Final growth measurements were taken at Little Rock on October 1; Fayetteville on October 10; and Hope on September 28.
Weather for 2009 at all three test sites is summarized.
2009 Average Monthly High and Low Temperatures
|Rating||(growth after 2 years)|
|Hydrangea quercifolia 'Little Honey'||5||-||-|
|Edgeworthia chrysantha 'Akebono'||5||-||-|
|Syringa 'Betsy Ross'||24||15|
|Halesia dipteral ssp. magniflora||15||0.3|
CJ = cannot judge due to insufficient information or other reasons
1 = Plant has performed well statewide
2 = Plant has performed well in zones 7a and 8.
3 = Plant performed fair statewide
4 = Plant performed fair zones 7a & 8
5 = Plant not recommended
6 = Plant performed well in 6b, poor in 7a & 8
7 = Plant performed fair in 6b, poor in 7a & 8
One-quart plants were donated by Briggs Nursery. Significant plant losses were observed during the first growing season. All four plants are dead at Hope, and three of the four died at Little Rock. By the end of 2010, all plants had died statewide. The yellow foliage was noticeably burned in our full sun plots.
One-quart plants were donated by Briggs Nursery. Three of the four plants in Little Rock died in the first growing season. All remaining plants at Hope, Little Rock and Fayetteville died in 2010. Flower buds will form on young plants.
#1 Plants were donated by the U.S. National Arboretum. Two of the four plants at Little Rock died in 2009. One plant died at Fayetteville in 2010. Average plant size statewide is 24" tall by 15" wide and a year-end growth index (GI) of 0.077 m3. There was no flowering in 2009. Flowers were observed in early April in 2010. Flowers are a bleached white.
#1 Plants were grown from seed by Dr. Lindstrom. The original plant of Halesia diptera v. magniflora came from Heronswood, and seed was collected off of this plant. There were no plant losses at the end of the first growing season. Three plants died at Fayetteville in 2010 and one plant at Little Rock. Average plant size statewide is 15" tall with a trunk caliper at 6" of 0.2."
One-quart plants were propagated from seed by Dr. Lindstrom. Seed was obtained from J.L. Hudson, Seedsman in La Honda, Calif. There were no plant losses at the end of the first growing season. One plant died at Hope in 2010. Average plant size statewide is 15" tall with a trunk caliper at 6" of 0.3." Significant rabbit predation affects plants in Fayetteville.
The Ornamentals team would like to express their sincere appreciation to Briggs Nursery and the U.S. National Arboretum for donating the plants for this season's trial.