UACES Facebook 2004 Plants

University of Arkansas Plant Evaluation Program
2004 Plants

2004 Final
May 2009

Plants initiated in Spring 2004 (5 years data):

This completes the tenth 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 March 19, 2004; Fayetteville was planted on March 19, 2004; Hope planted on March 20, 2004. 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 24; Fayetteville on December 11; and Hope on October 31.

Note: Significant losses occurred with the 2004 planting. Several frosts and freezes occurred after planting date and these weather occurrences had a significant, detrimental effect on many of the plants as noted below.

Ratings

       Width Height Caliper (6")
  Rating (growth after 5 years)
Osmanthus americanus 2 64 59  
Styrax confusus CJ 101 46  
Viburnum obovatum 'Christmas Star' ('Riefler's Dwarf') 2 44 63  
Clethra tomentosa 'Cottondale' 4 53 31  
Cleyera japonica CJ - -  
Indigofera heterantha CJ - -  
Buddleia loricata 4 - -  
Viburnum lantana 'Mohican' CJ - -  
Tetradium (Evodia) daniellii 3   137 3.4
Sequoiadendron giganteum [NO PICTURE] 5 - -  

Rating Key

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


  Osmanthus americanus

One-gal plants were purchased from Pine Ridge Gardens, London, AR. We were very impressed how well this plant grew statewide during the first growing season. Only two plants died statewide. The small white flowers appear in early April and mid-October. Average plant size after five years is 64" tall x 59" wide with a mean growth index (GI) of 4.289 m3. One female plant at Hope has been selected for further evaluation based on its overall favorable plant habit. Overall, this plant has performed well in zones 7a and 8.


Styrax confusus

One-gal plants were initiated by U of A from a Pine Ridge Nursery plant. Mortality for this plant was 100% at Fayetteville in the first year due to an unexpectedly harsh early spring environment and Hope for some unknown reason. One plant died at Little Rock in 2005 and a second in 2007 as the soil is very poor at that location. The foliage does have an attractive, silvery, underside. The attractive white star-like flowers develop in mid-May. Average plant size at Little Rock and Hope is 101" tall x 46" wide and a year-end growth index (GI) of 2.258 m3. Because of the high mortality, we cannot adequately rate this plant.


Viburnum obovatum ' Christmas Star' (received as 'Riefler's Dwarf')

One-gal plants of were initiated by cuttings at U of A from Univ. of Georgia plants. All four plants died at Fayetteville during the first growing season. Several plants at Hope and Little Rock began flowering in early September 2004 and continued to flower until late November. Flowers begin to appear in early April but significant flowering occurs in September through the first hard freeze. Cold fall temperatures caused the normally dark green foliage to turn a beautiful crimson. Average plant size at Hope and Little Rock is 44" tall x 63" wide with a mean growth index (GI) of 2.223 m3. This broadleaf is very impressive at Little Rock and Hope. It should be noted that other cultivars of this species have survived in Fayetteville, but tend to be deciduous during colder winters. Overall, this plant has performed well in zones 7a and 8.


Clethra tomentosa ' Cottondale'

One gallon plants were initiated by cuttings at U of A from a Woodlanders Nursery plant. In general, growth is good at Hope and Little Rock. Two of the four plants died at Fayetteville in the first year (2004) and two more died in 2006. Two of the four plants died at Little Rock in 2005 and one more in 2007. Plants flowered well from late July until early September. Average plant size is 53" tall x 31" wide. Overall, this plant has performed fair in zones 7a and 8.


Cleyera japonica

One gallon plants were initiated by cuttings at U of A from Univ. of Georgia plants. All four plants at Fayetteville died during the 2004 growing season. Mortality in the first year is likely a result of using very small plants and not a result of adaptability to Arkansas summer conditions. By the end of 2007 only one plant remained alive, and this is at Little Rock. Average plant size at Little Rock is 45" tall x 43" wide. Because of the high mortality, we cannot adequately rate this plant.


Indigofera heterantha

One quart plants were initiated by cuttings at U of A from Univ. of Georgia plants. Mortality statewide was high with eight of the 12 plants dying in the first growing season. The remaining plant died at Fayetteville in 2005. Mortality is likely a result of using very small plants and not a result of adaptability to Arkansas summer conditions. Surviving plants at Hope and Little Rock flowered from early June until late September. Average plant size at Hope and Little Rock is 61" tall x 110" wide. The plant was a favorite of rabbits in Fayetteville. Because of the high mortality, we cannot adequately rate this plant.


Buddleia loricata

One quart plants were grown from seed obtained from Silverhill Seed in South Africa. Mortality statewide was high with nine of the 12 plants dying in the first growing season (2004). All four plants at Fayetteville died during the 2004 growing season. Mortality is likely a result of using very small plants and not a result of adaptability to Arkansas summer conditions. The remaining plants statewide died during 2005. This species is one parent of the new hybrid B. 'Silver Anniversary' (the other parent is B. crispa).


Viburnum lantana ' Mohican'

One gallon plants were initiated by cuttings at U of A from Greenleaf Nursery plants. Three of the four plants at Fayetteville died during the first growing season. As of the fall of 2007 only one plant remained at Hope. Mortality at Fayetteville and poor performance at Little Rock and Hope is likely a result of using very small plants and not a result of adaptability to Arkansas summer conditions. Plant size at Hope is 39" tall x 16" wide. Because of the high mortality, we cannot adequately rate this plant.

Shoot Width Height
Bar chart showing Shoot Width for Viburnum lantana 'Mohican'. Link to larger picture. Select back button to return.   Bar chart showing Shoot Height for Viburnum lantana 'Mohican'. Link to larger picture. Select back button to return.  
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Tetradium (Evodia) daniellii

Two-gallon container plants were donated by J. Frank Schmidt Nursery. Survival and growth statewide was very good during the first year. One plant died at Hope in 2005. The 2007 Easter freeze killed three of the four plants in Fayetteville to the ground. Statewide, average shoot height is 137" tall with a trunk caliper measured at 6 inches of 3.4". Average plant size in the fall of 2008 is very inconsistent statewide. For shoot height: Hope, 115"; Little Rock, 188"; Fayetteville, 109". Shoot caliper at 6": Hope, 3"; Little Rock, 4.4"; Fayetteville, 2.6". Both flowers and developing fruit provide ornamental interest. Flowers appear in late June and early July. Overall, we feel Tetradium performed fair statewide.

Trunk Diameter Height
Bar chart showing Trunk Diameter for Tetradium (Evodia) daniellii. Link to larger picture. Select back button to return.   Bar chart showing Shoot Height for Tetradium (Evodia) daniellii. Link to larger picture. Select back button to return.  
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Sequoiadendron giganteum

Bareroot liners were purchased from Lawyers Nursery. Mortality was very high statewide as indicated by the fact that 10 of the 12 plants were dead by mid-summer of the first year (2004). All four plants died during the growing season at Hope. The final remaining plant at Fayetteville died during the growing season in 2008. The high mortality is likely a result of using small bareroot plants and not a result of adaptability of this plant to grow in Arkansas. Based on the performance we would not recommend this plant.

Trunk Diameter Height
Bar chart showing Trunk Diameter for Sequoiadendron giganteum. Link to larger picture. Select back button to return.   Bar chart showing Shoot Height for Sequoiadendron giganteum. Link to larger picture. Select back button to return.  
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The Ornamentals team would like to express their sincere appreciation to the cooperating nurseries (J. Frank Schmidt Nurseries, Dr. Michael Dirr- University of Georgia) for donating the plants for this season's trial and to the Arkansas Green Industry Association for financial support.