University of Arkansas Plant Evaluation Program

2006 Plants/ Arkansas Plant Evaluation Program 2006 Report

[Program information (data, reports, photographs) can be found on the internet at: http://www.uark.edu/campus-resources/cotinus/arboretum_html/planteval.html]

January 2007

Plants initiated in Spring 2006 (first year data):

This completes the eighth year of the statewide plant evaluation program. The current team of cooperators includes Dr. Jim Robbins, Dr. Jon Lindstrom, and Manjula Carter.

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 1/3 of limbs. SHRUBS are NOT pruned. Final growth measurements were taken at Little Rock on October 20; Fayetteville on October 31; and Hope on October 17.

Weather data at all three test sites is attached (see attached graph).

Loropetalum chinense

One-quart plants were initiated by the UofA from plants at Westwood Gardens, Fayetteville. All four plants died at Hope during the first growing season. Average plant size at Little Rock and Fayetteville is 9” tall x 15” wide and a year-end growth index (GI) of 0.028 m³.

Cercis canadensis ‘Avondale’

One-quart plants were initiated by UofA from a plant from Forestfarm. Two plants died at Hope and one plant at Little Rock in the first year. Significant flowering was noted on the older stems at all three locations in mid-October. Average plant size at Little Rock and Hope is 23” tall x 19” wide and a year-end growth index (GI) of 0.129 m³.

Leucothoe keiskei ‘Royal Ruby’

One-quart plants of were initiated from liners purchased from Griffith Propagation, Watkinsville, GA. Ten of the twelve plants are dead statewide. Only two plants are alive in Little Rock. Average plant size at Little Rock is 9” tall x 7” wide and a year-end growth index (GI) of 0.006 m³.

Sorbaria sorbifolia

One-quart plants were initiated from seed obtained from J.L. Hudson, seedsman. All twelve plants are alive statewide. Plants flowered in the first year. Flowering begins in mid-July and continues through early September. Average plant size is 16” tall x 12” wide and a year-end growth index (GI) of 0.049 m³.

Ilex x ‘Cherry Bomb’

Two-gallon plants were donated by Stephen F. Austin Arboretum in Texas. Two plants died at Little Rock during the first summer. Average plant size is 19” tall x 18” wide and a year-end growth index (GI) of 0.092 m³.

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.