University of Arkansas Plant Evaluation Program
2005 Final Report
Plants initiated in Spring 2005 (5 years data):
This completes the eleventh 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 29, 2005; Fayetteville was planted on May 9, 2005; Hope planted on April 14, 2005. 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 23; Fayetteville on December 14; and Hope on September 30.
|Rating||(growth after 5 years)|
|Illicium parviflorum 'Forest Green'||2||49||54|
|Magnolia x 'Wada's Memory'||6||89||2|
|Taxus baccata 'Carl Totemeier'||4||24||11|
|Buddleia 'Asian Moon'||1||76||101|
|Eucalyptus pauciflora v. niphophila||5||-||-|
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-gal plants were initiated by the UofA from plants at the University of Georgia . Plants were growing well statewide with no plant losses in 2005, however, 3 of the 4 plants died at Fayetteville in 2006. Plants were noted to flower at Hope in May and continue sporadically through September. Average plant size statewide is 38" tall x 38" wide and a year-end growth index (GI) of 1.254 m3. This may be misleading since the only remaining plant at Fayetteville is very small (15" tall x 6" wide). Average plant size at Hope and Little Rock is 49" tall and 54" wide (GI=1.88 m3). Overall, this plant is performing well in zones 7a and 8 (2).
One-gal plants were initiated by U of A from a plant from the U.S. National Arboretum. Plants are growing very well at Hope and Little Rock but not Fayetteville. All 4 plants died at Fayetteville during the first growing season. Flowering started at Hope on May 3 and ended on May 20. Significant red fruits were noted in October but they are small in size. Mealybug was a serious problem at Hope. Average plant size at Little Rock and Hope is 37" tall x 69" wide and a year-end growth index (GI) of 2.310 m3. Overall, this plant is performing well in zones 7a and 8 (2).
One-gal plants of were initiated by cuttings at U of A from Stephen F. Austin Arboretum plants. Plants did do well at Hope and Little Rock during the first growing season but struggled at Fayetteville. No plants survived the first winter which was relatively mild. This broadleaf evergreen would not be recommended for Arkansas (5).
One gallon plants were initiated by cuttings at U of A from a Forestfarm Nursery plant. Plants have performed well statewide with no mortality in the first year. One plant died at Fayetteville in 2008. Two plants died in 2009 in Little Rock due to excessive rainfall and an apparent intolerance of this plant (and others in this family) to poor drainage. Average plant size statewide is 89" tall with a trunk caliper of 2.0". The overall habit is an upright oval. Foliage on most plants looks pretty ragged in late summer. Two plants did flower at Hope starting in early March. Overall we rate this plant as performing well in 6b and poor in 7a and 8 (6). In Fayetteville, this plant was killed to the ground in 2007.
One gallon plants were initiated by John Kirby. Plants have done fairly well at Hope and Little Rock. Three of the four plants died at Fayetteville in 2007 and the final plant died in 2008. The full sun exposure at the trial locations does not seem ideal for this yellow foliaged plant. Lack of rainfall in 2007 also contributed to this plant's decline in Fayetteville. Average plant size at Hope and Little Rock is 24" tall x 11" wide. Overall, this plant is performing fair in zones 7a and 8 (4).
One gallon plants were initiated by cuttings at U of A from Dr. Lindstrom's breeding program. Plants have performed exceptionally well statewide. One plant died at Little Rock in 2006 and two died during the growing season at Little Rock in 2008. Plants are very uniform across the three sites. Plants began flowering at Hope in mid-June and continued until late October. Average plant size is 76" tall x 101" wide and a year-end growth index (GI) of 10.764 m3. Even with the unexplained plant losses at Little Rock, we still rate this plant as performing well statewide (1).
One quart plants were purchased from Forestfarm Nursery. Considering how small the plants were, plants performed well in the first growing season (2005). The sole remaining plant at Little Rock died in 2008. Overall, this plant would not be recommended for Arkansas (5).
The Ornamentals team would like to express their sincere appreciation to the cooperating nurseries (Dr. Michael Dirr- University of Georgia and Dr. David Creech, Stephen F. Austin Arboretum) for donating the plants for this season's trial and to the Arkansas Green Industry Association for financial support.