November 8, 1999
by Dr. James A. Robbins, University of Arkansas Cooperative Extension Service

This completes the first year of the statewide plant evaluation program. Considering that the concept was first discussed in December of 1998, and that the three test sites needed to be established from scratch, the first year appears to be a success.

The current team of cooperators includes Dr. Jim Robbins, Dr. Jon Lindstrom, Dr. Gerald Klingaman, Scott Starr, and Janet Carson.

The three test (Attachment A) sites are Hope Research Center (zone 8a), Little Rock/Cammack property (zone 7a), and Fayetteville Horticulture Research farm (zone 6 b). 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. Plants groups are planted together (i.e. trees are planted together). Trees are spaced 10’ apart, shrubs 6’ apart, and herbaceous perennials 4’ apart. For shade requiring plants, separate evaluation sites were established under natural shade at all three test sites. Little Rock site was planted on March 10; Fayetteville was planted on March 11; Hope planted on April 13. At Hope and Fayetteville plants were irrigated by a drip system and at Little Rock by hand watering. Plants were fertilized and mulched after planting. Post-emergent herbicides were used at all three test sites. No disease or insect control was implemented in 1999. The oak and Styrax were pruned following final growth measurements to establish a tree-like habit. Pruning consisted of removing the bottom 1/3 of limbs. Final growth measurements were taken at Little Rock on October 28; Fayetteville October 25; and Hope on October 19.

In general, the best growth for the 15 shrubs and 2 trees was the Little Rock site. Plants at the Little Rock site do receive a few hours of shade generally during the morning hours. Fayetteville and Hope are very exposed, full sun sites. The Fayetteville site is characterized by consistent winds.

Arkansas experienced above normal temperatures and below normal rainfall at all three sites in 1999.

Rhododendron Autumn Amethyst^TM

Flowerwood Nursery donated 3-gal plants. Performance appears to be excellent at all three sites. Rebloom was noted in late July and continued into fall. The plant appears to be slightly wider (32") than tall (25"). This is the largest of the three being evaluated. Best growth was in Little Rock with Fayetteville a close second. Plants at both sites grew almost ¼ of a meter in volume during 1999.

Rhododendron Autumn Coral^TM

Flowerwood Nursery donated 3-gal plants. Performance appears to be excellent at all three sites. Rebloom was most significant and consistent on this cultivar. Rebloom was noted in mid-July and continued through the fall. Plant shape appears to be wider (23") than tall (14"). Growth at the Little Rock site was nearly double the other two locations.

Rhododendron Autumn Embers^TM

Flowerwood Nursery donated 3-gal plants. Performance appears to be excellent at all three sites. Like the other three Encore series plants, winter hardiness is a critical factor to be monitored in the future. Rebloom was the least on this cultivar. Some rebloom was noted in the fall. Overall shape is similar to Autumn Coral. The Little Rock site was again noted for the greatest increase in growth.

Camellia sasanqua Hot Flash^TM

Flowerwood Nursery donated 3-gal plants. Performance appears to be good at all three sites. Flowering has not been observed as of yet at any of the test sites. Plant shape is almost as wide (23") as it is tall (19"). Growth rate at Fayetteville and Hope was nearly equal. Performance at Little Rock it is felt was limited by a lack of irrigation during the extended hot and dry periods of the summer.

Ilex x Little Red^TM

Flowerwood Nursery donated 5-gal plants. Performance was good at all three test sites. The best growth rates were observed in Little Rock where the plants increased in growth and average 77 in³. On average the plant is slightly taller (41") than it is wide (36").

Ilex x Oakleaf^TM

Flowerwood Nursery donated 5-gal plants. Performance was good at all three test sites. The plant is clearly taller (49") than it is wide (21"). A strong pyramidal shape is developing without shearing.

Ilex x Dixie Dream^TM

Flowerwood Nursery donated 7-gal plants. Performance was good at all three test sites. Plants have an upright pyramidal shape (34" tall by 23" wide).

Abelia x grandiflora ‘Sunrise’

Greenleaf Nursery donated 3-gal plants. Performance was fair at all three sites. Abelia was clearly struggling at Hope and Fayetteville. Spider mites were noted on the plants at Fayetteville. Growth rate at Little Rock was the best and that rate was nearly double that of Hope and 7 times that of Fayetteville. The plant offers a unique change in foliage variegation during the season that will likely be a plus in the consumer market. Average plant width (26") is twice the height (13").

Ligustrum ‘Green Meatball’

Hines Nurseries donated 5-gal plants. Performance was good at all three sites. Based on growth during the 1999 season a serious question arises to the shape of this plant. While the cultivar name suggests a rounded plant, the plants developed a wispy, open habit at all three sites. Vigorous new growth developed in all directions on this plant.

Itea virginica ‘Henry’s Garnet’

Greenleaf Nursery donated 1-gal plants. Performance was good at all three sites. Plants were observed to be suckering at all three sites by the end of the season. Typically maroon fall color was observed by late October at Fayetteville and Little Rock. Flowers appeared for a brief period in early May.

Rhaphiolepis Bay Breeze

Hines Nurseries donated 1-gal plants. Performance was good at all three sites. A slightly showy flower display was noted in spring and then again in mid-summer. Plant habit is clearly spreading (19") rather than tall (9"). Foliar leaf spot was noted on the plants.

Loropetalum Plum Delight

Hines Nurseries donated 1-gal plants. Performance was mixed. Plants grew vigorously in Little Rock but struggled at Fayetteville and Hope. Plant color was a deep rich maroon in Fayetteville but was a more washed-out brown purple at the other two sites.

Lagerstroemia x ‘Pocomoke’

Morningside Nursery donated liners. Considering the size of the initial liners this is remarkable growth and performance for small plants planted out in field conditions. Flowers started to appear in mid-July but peaked toward the end of August. Of the two dwarfs being tested, this appears to be the best. Average shape is 12" wide by 8" tall.

Lagerstroemia x ‘Chickasaw’

Morningside Nursery donated liners. Like ‘Pocomoke’, considering the size of the initial liners, it is amazing what growth and survival occurred. ‘Chickasaw’ almost teased us when it came to flowering. Beautiful, glossy, red ceramic flower buds appeared in July but were slow to open until late August or into early September. Buds almost appeared ‘blind’ as the petals barely emerge from the calyx. The overall impact of the flower display was not as good as that seen with ‘Pocomoke’.

Lagerstroemia indica ‘Velma’s Royal Delight’

Morningside Nursery donated liners. Peak flowering for this clear purple selection was noted in late July.

Greenleaf Nursery donated 5-gal plants. Growth was good at all three test sites. Peak flowering was in mid to late May. New growth on plants in Little Rock were covered by aphids early in the season but this did not last or affect the overall plant growth. Growth increases were very similar at all three test sites.

Oak hybrid

Pittman Nursery donated 1-gal plants. A preliminary assessment is that this plant is Quercus x comptoniae. Growth was good at all three sites and fairly consistent between sites.