University of Arkansas Plant Evaluation Program
2006 Final Report
Plants initiated in Spring 2006 (5 years data):
This completes the twelfth 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 18, 2006; Fayetteville was planted on May 17, 2006; Hope planted on April 12, 2006. 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.
|Rating||(growth after 5 years)|
|Cercis chinensis 'Avondale'||3||81||59|
|Leucothoe keiskei 'Royal Ruby'||5||-||-|
|Ilex x 'Cherry Bomb'||4||37||37|
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 initiated by the U of A from plants at Westwood Gardens, Fayetteville. All four plants died at Hope during the first growing season. One plant died in Fayetteville in 2006 and the remaining three in 2007. Average plant size on the three remaining plants at Little Rock is 43" tall x 53" wide and a year-end growth index (GI) of 1.509 m3. Surprisingly, the mature (stock) plant in Fayetteville is performing the best of any Loropetalum grown there. So far, we rate performance as fair in zones 7a and 8 (4).
One-quart plants were initiated by the U of A from a plant from Forestfarm. Two plants died at Hope and one plant at Little Rock in the first year. Two plants died at Fayetteville in 2007. Significant flowering was noted on the older stems at all three locations in mid-October and early April. The flower display is exceptional on this plant. Average plant size is 81" tall by 59" wide and a year-end growth index (GI) of 2.814 m3. The tallest plants are at Hope (zone 8; 98") and decrease in size as you go north to Fayetteville (zone 6; 63"). A serious insect problem was noted at all three sites in 2009. The redbud leaf roller (Fascista cercerisella) results in leaves looking very disfigured by late summer. So far, we rate statewide performance as fair (3).
One-quart plants of were initiated from liners purchased from Griffith Propagation, Watkinsville, Ga. Ten of the 12 plants died within the first year. The remaining two plants at Little Rock died during 2007. Based on these results, this broadleaf evergreen would not be recommended for Arkansas (5).
One-quart plants were initiated from seed obtained from J.L. Hudson, seedsman. One plant died during 2007 in Little Rock. Plants flowered in the first year. Flowering begins in mid-July and continues through early September. Average plant size is 48" tall by 52" wide and a year-end growth index (GI) of 1.797 m3. So far, the plant is performing well statewide, but especially well in Fayetteville (1). This plant suckers extensively.
Two-gallon plants were donated by Stephen F. Austin Arboretum in Texas. Two plants died at Little Rock during the first summer. All plants are dead in Fayetteville. Average plant size is 37" tall by 37" wide and a year-end growth index (GI) of 0.912 m3. Leaves at Hope were noted with significant frost damage in spring 2009 even though the temperature was just barely below freezing. Ilex integra blood in this hybrid likely makes this most suitable in zone 8b-9. A few marble-sized fruits were first observed at Hope in 2009. Moderate fruiting was observed on the Hope plants in 2010. So far, the plant is performing fair in zones 7a and 8 (4).
The Ornamentals team would like to express their sincere appreciation to Dr. David Creech, Stephen F. Austin Arboretum, for donating the plants for this season’s trial.