UACES Facebook 2002 Plants

University of Arkansas Plant Evaluation Program
2002 Plants

2006 Final Report
January 2007

Plants initiated in Spring 2002: 

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), the Little Rock/Cooperative Extension Service property (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, 2002; Fayetteville was planted on April 5, 2002; Hope planted on April 5, 2002. 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 210; Fayetteville on October 31; and Hope on October 17.

Weather for 2006 at all three test sites is summarized

2006 Average Monthly High and Low Temperatures

Bar chart showing 2006 Average Monthly High and Low Temperatures.  Link to larger picture. Select back button to return.

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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

Average Plant Size

Bar chart showing Average Plant Size for Fayetteville, Little Rock, and Hope. Link to larger picture. Select back button to return.

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Acer saccharum Fall FiestaTM

Bailey Nursery donated 8' BR plants. Performance has been fair at Little Rock and Hope and good in Fayetteville. Tree height decreases as we go from zone 6 to zone 8 (Fayetteville: 158"; Little Rock 155", Hope 83"). Statewide average tree height is 132" with a trunk caliper @ 6" of 2.3". Two of the three trees died at Hope in the first year of planting (2002). A nice orange-red fall color developed on the Fayetteville trees in late October 2006.



Magnolia grandiflora ' Hasse'

Briggs Nursery donated 1-gal plants. Performance has been good so far. Only one tree has died statewide at that was at Little Rock. Based on the color variation in underside leaf surface pubescence, we wonder if we have more than one clone. Two trees in Fayetteville flowered for the first time in June and July 2005. Plants really took off in growth in the second year increasing in height statewide by 32". Statewide average tree height is 141" with a trunk caliper @ 6" of 3.7". 



Magnolia ×' Vulcan'

Briggs Nursery donated 1-gal plants. Performance has been good at Hope, fair at Little Rock, but abysmal in Fayetteville. At Fayetteville in 2003, two plants died and the third killed to the ground with limited re-growth the following spring. Plants flowered at Hope and Little Rock in 2005. Large, goblet-sized purple flowers appear in late March/early April. Foliage is distorted by an unidentified leaf spot in Little Rock and Hope. Statewide average tree height is 1102" with a trunk caliper @ 6" of 2.2". Magnolia 'Vulcan' would be best suited for use in the central and south parts of Arkansas. Winter protection may be needed for young plants in north Arkansas; however, such plants may become more cold-hardy as they reach a larger size.



Clethra alnifolia 'Sixteen Candles'

Griffith Propagation Nursery donated 2" liner plants. Both clones of Clethra tested performed very poorly at all three sites. By the end of 2004 all 9 plants are dead at all three test sties. If it had simply been this cultivar, we would have concluded high mortality was related to small plant size. However, the sister clone 'White Dove', also performed poorly during an Arkansas summer. 



Clethra alnifolia White DoveTM

Flowerwood Nursery donated 3-gal container plants. Similar to sister seedling, 'Sixteen Candles', 'White Dove' struggled during an Arkansas summer. Flowering is about 1 week later than 'Sixteen Candles'. Statewide all plants are dead. 



Chamaecyparis thyoides ' Emily'

Cuttings were rooted from University of Georgia plants and planted as a 1-gal. Growth rate was outstanding at all three test sites. This might be a good substitute for those looking for Juniperus virginiana. Average plant size statewide is 111" tall by 114" wide. Plants are wider than they are tall at Fayetteville (92" tall x 109" wide). 



Cliftonia monophylla Chipola PinkTM

Flowerwood Nursery donated 3-gal container plants. Six of the nine plants planted, including all the plants in Fayetteville, died during the first summer. Only two plants remain at Hope (zone 8). Average plant size on remaining plants is 33" tall x 35" wide. Plants display a lovely soft pink flower in mid-April at Hope.



Daphniphyllum macropodum

1-gal plants were purchased from Colvos Creek Nursery. We are very impressed with the performance of this broadleaf evergreen in Little Rock and Hope during the first two years even though it was planted in full sun at all three sites. Most of the growth continues to be vertical. This plant would benefit from pruning at an early age which we do not do in our program. Plants in Fayetteville were seriously affected by cold weather in October and November of 2002 and all three died. The bark on all three plants has split at the base of the plant. All three plants growing in Little Rock died in 2004. The deaths at LR would appear to be related to root rot in our heavy soil and a very wet spring. All plants are dead statewide by the end of 2005. 



Distylium myricoides

1-gal plants were purchased from Nurseries Caroliniana. Performance was good at all three sites. Two of the nine plants are dead statewide. Plants flowered in the first year. Average final plant size was 32" tall by 773" wide (broader than tall). Plants flowered the last 2 weeks in March in Fayetteville, Little Rock and Hope. Up close the flower is exquisite. This might make a nice spreading broadleaf evergreen in place of junipers or hollies. 


Ilex × koehneana ' Martha Berry'

Flowerwood Nursery donated 3-gal container plants. Plant growth was good at all 3 sites. Average final plant size was 82" tall by 61" wide. Plants are significantly shorter at Fayetteville (71") compared to Little Rock (95") and Hope (99"). Foliage is a dark blue-green. New growth on this holly was slow to harden-off in Fayetteville and was damaged by the first frost of the season (2006). Fruits were first noticed in 2006 in late October.



Michelia skinneriana

1-gal plants were purchased from Nurseries Caroliniana. Performance was good at Hope and Little Rock. All plants are dead at Fayetteville (zone 6). Average plant size was 83" tall by 85" wide. Foliage is a very clean, medium green. Plants have a unique cream-white flower that is mostly hidden by the evergreen foliage. Flowers appear in early April and then sporadically through October. 



Prunus lusitanica

1-gal plants were purchased from Forestfarm Nursery. Growth was good at Hope. All plants are dead in Fayetteville and Little Rock. Plants flowered in Little Rock in early May and fruits were noted in mid-September. Average final plant size was 47" tall by 47" wide. 



Rhododendron ' Peppermint Twist'

Briggs Nursery donated 4" liner plants and this was truly a remarkable success story in Little Rock and Hope for the first two years. The sole remaining plant died in Little Rock in 2006. Plants, while not thriving, did well considering they were grown in full Arkansas sun. Plants in Little Rock flowered in late April, 2004 and lasted for about 2 weeks. 



Thuja plicata 'Spring Grove'

1-gal plants were purchased from Nurseries Caroliniana. Here is an interesting situation since we now understand that Thuja × 'Green Giant' (2001 plant) and this cultivar are likely identical. Plants grew exceptionally well at all three sites. One plant died at Little Rock in 2004 due to what looks like a root rot. Average final plant size was 137" tall by 68" wide. 



Trochodendron aralioides

1-quart plants were purchased from Colvos Creek Nursery. Plants started fine but were killed by the hot Arkansas summer. A shadier location is suggested for future plantings.

Did not survive the first year, no photo or charts available.



Ceanothus x delilianus ' Henri Desfossé'

Hines Nurseries donated 5-gal container plants. The plants came labeled as 'Gloire de Versailles' but they are actually the cultivar 'Henri Desfossé. 'Gloire de Versailles' has larger, broader leaves and bigger flower panicles. This plant is probably the star for the year. These plants begin to flower in May and as of late October were still in flower. Unbelievable flower display and the fruits mature with a beautiful cherry red that lasts until a hard frost. Average final plant size was 78" tall by 115" wide. One plant has died (Little Rock). One problem associated with this plant in Fayetteville is its tendency to continue growth late into the season. This is especially apparent during the years with a dry summer. With the resumption of rain in the fall, plants grow and flower profusely but then suffer damage with the onset of colder weather.


The Ornamentals team would like to express their sincere appreciation to the cooperating nurseries (Flowerwood Nurseries, Briggs Nursery, Dr. Michael Dirr - University of Georgia, Griffith Propagation Nursery, and Hines Nurseries) for donating the plants for this season's trial and to the Arkansas Green Industry Association for financial support.