December 7, 2000 (.pdf file requires Adobe Acrobat)

This completes the second year of the statewide plant evaluation program. The current team of cooperators includes Dr. Jim Robbins, Dr. Jon Lindstrom, Dr. Gerald Klingaman, Scott Starr, Dr. James Cole, Manjula Carter, Matthew Pelto, and Janet Carson.

The three test sites are the Hope Research Center (USDA cold hardiness zone 8a), the Little Rock/Cammack property (zone 7a), and the 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, 1999; Fayetteville was planted on March 11, 1999; Hope planted on April 13, 1999. 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 in 1999 or 2000. In both years, 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 November 2; Fayetteville on October 19; and Hope on November 30.

In general, the best growth for the 15 shrubs and 2 trees continues to be 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 an extremely hot and dry summer at all three sites in 2000 (see graph). For example, at Little Rock, the average high temperature during the month of August was 102° F, or 12 degrees above the normal.

Rhododendron Autumn Amethyst^™

Flowerwood Nursery donated 3-gal plants. Performance appears to be good at all three sites. Flowers were first noted in early March and continued through mid-April. Significant re-bloom was noted in late August and continued until each site had a hard freeze. The plant appears to be slightly wider (40") than tall (29"). This is the tallest of the three Encore azaleas being evaluated. The largest increase in growth for 2000 was in Little Rock with Fayetteville a close second.

Rhododendron Autumn Coral™

Flowerwood Nursery donated 3-gal plants. Performance appears to be good at all three sites. Flowering notes indicate that Coral started flowering 1 week after Amethyst in the spring but flowered for a similar period of time. Significant re-bloom was noted in mid-July and continued through until each site had a very hard freeze. Plant habit is clearly wider (31") than tall (16"). Habit of Coral is very similar to Embers.

Rhododendron Autumn Embers™

Flowerwood Nursery donated 3-gal plants. Performance appears to be good at all three sites. Spring flowering period is very similar to Coral. Summer/fall rebloom appears to begin a little later than Amethyst and Coral. Overall shape is similar to Autumn Coral (33" wide x 17" tall).

Camellia sasanqua Hot Flash™

Flowerwood Nursery donated 3-gal plants. Performance appears to be good at all three sites. Our first flowers opened in December of 1999 just after we completed our annual report. The flower color is a deep rose color. Plant shape is slightly wider (27") than tall (21"). The overall size at each of the 3 sites is very similar and consistent after 2 years.

Ilex x Little Red^™

Flowerwood Nursery donated 5-gal plants. Performance was good at all three test sites. The plant is slightly taller (76") than it is wide (63"). This plant has good landscape qualities with the burgundy color to the emerging foliage, clean foliage, and 5-6 mm red fruits.

Ilex x Oakleaf™

Flowerwood Nursery donated 5-gal plants. Performance was good at all three test sites. The plant is clearly taller (85") than it is wide (34"). A strong pyramidal shape is developing without shearing. This holly lends itself well to a narrow screen or hedge plant.

Ilex x Dixie Dream™

Flowerwood Nursery donated 7-gal plants. Significant flowering was noted in late May and early June. Significant fruit production was noted starting in October. These fruits are smaller than Little Red. Performance was good at all three test sites. Plants have an upright pyramidal shape (53" tall by 39" wide) without pruning.

Abelia x grandiflora 'Sunrise'

Greenleaf Nursery donated 3-gal plants. Performance was good at Little Rock and Fayetteville. Abelia was clearly struggling at Hope. Flowering began in mid June and continued sporadically into fall. Significant reversion from the variegated form back to a green-leafed form was noted. The variegation does not appear to be very stable. Average plant width (35") is twice the height (17"). Based on performance and reversion problems the program will likely not recommend this cultivar.

Ligustrum 'Green Meatball'

Hines Nurseries donated 5-gal plants. Performance was good at all three sites. In last years report we noted the plants developed a wispy, open habit at all three sites. Plant habit has changed significantly this year. It appears that the plant put on tremendous vertical growth last year but filled that in this year. The shape is approaching a ball in the second year (59" wide x 52" tall). Peak flowering was noted in May.

Itea virginica 'Henry's Garnet'

Greenleaf Nursery donated 1-gal plants. Performance was good at all three sites. Flowering generally began at the end of April and continued for one month. A real asset to this plant is the rich maroon fall color that is intense by Thanksgiving. Plants are beginning to spread quickly by rhizomes. Average plant size is 28" tall by 52" wide.

Rhaphiolepis Bay Breeze â

Hines Nurseries donated 1-gal plants. Performance was good at all three sites. Flowering begins in early April and then again late summer. It did not flower at Fayetteville this year. The plant develops a very attractive deep maroon winter foliage color that makes a nice backdrop for the light pink flowers in early spring. Plant habit is clearly spreading (28") rather than tall (13"). The most significant growth increase this year was at Hope, followed by Little Rock, and then Fayetteville. The largest plants continue to be at Little Rock. Foliar leaf spot was noted on the plants.

Loropetalum chinense Plum Delight â

Hines Nurseries donated 1-gal plants. Performance was mixed again this year. Plants grew vigorously in Little Rock but struggled at Fayetteville and Hope. For some unknown reason ¾ plants at Hope died this growing season and ¼ died at Fayetteville. Plant color was a deep rich maroon in Fayetteville but was a more washed-out brown purple at the other two sites. The fact that Hope and Fayetteville are very open, full sun sites, suggests Loropetalum would benefit from some sun protection at some point during the day. Flowering began in late February and continued until a hard late spring freeze. Plants tend to throw late season flowers based on temperatures and precipitation. When in flower this plant is hard to beat. Loropetalum did not flower at Fayetteville this year. Plants at Little Rock are enormous considering the age and size of the original plant. Average width is 106" x 59" tall at Little Rock. Plants are considerably smaller at Hope and Fayetteville.

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 early July but peaked toward the end of August. Plants continue to flower into September. Of the two genetic dwarfs being tested, this appears to be the best. Average size is 23" wide by 12" 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'. Average size is 13" wide by 9" tall.

Lagerstroemia indica 'Velma's Royal Delight'

Morningside Nursery donated liners. This crapemyrtle began flowering in mid-June and continued for months (mid-September)! Dr. Lindstrom at Fayetteville is extremely impressed with the duration of flowering, flower color, and plant size. Powdery mildew was noted at the Little Rock location. Average size is 30" wide by 23" tall.

Styrax japonicus

Greenleaf Nursery donated 5-gal plants. Growth was good at all three test sites. Dramatic flowering is from mid-April to early May. Again this year the Fayetteville site noted scorching of the foliage in mid August due to the extended hot and dry weather. Growth increases were very similar at all three test sites. One minor problem is the appearance of basal watersprouts and suckers that would require constant removal to maintain a clean landscape appearance. The average plant height is 114" with a trunk diameter at 6" of just over 2".

Quercus 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. Since this plant is of seed origin, the plant habit is beginning to fall into two categories. One group is developing a nice open tree canopy, while those in the second group show a strong tendency to produce many recurving lower branches that will make this plant difficult to work with and require more initial pruning maintenance. The average plant height is 107" with a trunk diameter at 6" of just under 2".

The Ornamentals team would like to express their sincere appreciation to the cooperating nurseries (Flowerwood Nurseries, Hines Nurseries, Greenleaf Nursery, Morningside Nursery, and Pittman Nursery) for donating the plants for this season’s trial and to the Arkansas Nurserymen’s Association for financial support.

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