RESEARCHERS PUT UNDERUSED PLANTS TO THE TEST

FAYETTEVILLE, Ark. - University of Arkansas horticulture professor Jon Lindstrom would like to see Arkansans plant a larger variety of plants in their home gardens - but only if they can find specimens that can withstand the capricious climates of the Natural State.

Lindstrom runs the Fayetteville portion of a three-site Plant Evaluation Program designed to help people make such educated choices about plants in their gardens. The project, directed by Jim Robbins of the Cooperative Extension Service in Little Rock, examines the hardiness of landscaping plants in Arkansas’ three USDA growing zones - 6, 7 and 8.

"People get into a rut with their plant material choices," Lindstrom said. "The goal here is to get people to expand their palettes."

Each year, the researchers choose 15-20 varieties of plants to put in at test sites in Little Rock (zone 7), Hope (zone 8) and Fayetteville (zone 6). They choose plants that seem to be underused in Arkansas landscapes and ones that might be adaptable to Arkansas’ three plant hardiness zones. They focus on fall-blooming perennials that can be used as screens, ground covers or hedges in landscaping.

"There’s a lot of new plant material coming out all the time, and nurseries want to know whether these new plants are cold hardy," Lindstrom said. "In horticulture, new plants are what drives the market."

In the Plant Evaluation Program, the plants are grown and examined for five years - if they make it that long.

"This is something you can’t do in one or two years," Lindstrom said. He points to the last three winters as an example: 1998-99 and 1999-2000 were quite mild winters, but 2000-2001 brought ice storms and set record low temperatures in Northwest Arkansas for November and December. Many of the Northwest Arkansas plants did not survive the cold.

"In fact, plants that do fine in the other two-thirds of the state often do not do well in Northwest Arkansas," Lindstrom said. He explained that often when people move to Fayetteville from Little Rock, they seek similar plants for their gardens, only to be told that those particular varieties do not grow here.

The researchers at the different stations planted the first set of plants in 1999. The plants come from nurseries across the South and from propagation by the researchers at the three sites. The plants under evaluation range from rhododendrons and camellias to oaks and pear trees.

Lindstrom said that so far in the program, a few plants have fared well in all three zones. They include:

Fragrant sumac (Rhus aromatica) sports soft yellow flowers in April, with red fruit following in May. Its fall color ranges from oranges to reds to purples. The plant is an Arkansas native and adapts well to poor soil. There is a cultivar called 'Gro-Low’ that reaches three to four feet in height and six to ten feet in width.

Bush honeysuckle (Diervilla lonicera) adapts well to different environments and can be used as a border on banks. In late May it produces small yellow flowers that continue throughout the summer.

Chinese abelia (Abelia chinensis) begins flowering in late July and continues into September. The pink and white blooms attract butterflies throughout the summer. The plant dies back during Northwest Arkansas winters but returns the next year to bloom on new growth. Plants further south can reach 4 to 5 feet tall, and their height can be controlled with late winter pruning.

Virginia sweetspire (Itea virginica) can be used as a border plant. This ground cover is also native to Arkansas. It sports white flowers in May, and the leaves turn garnet in the fall.

Dixie DreamT holly (Ilex) grows taller than it does wide. It sports flowers in late May and early June and small red berries starting in October. The plants have an upright, pyramid shape without pruning.

The current team of cooperators working on the Plant Evaluation Project includes Robbins, Lindstrom, Gerald Klingaman, Scott Starr, James Cole, Manjula Carter, Matthew Pelto and Janet Carson.

For a complete listing of plants included in the Plant Evaluation Program and more information on the results, please see http://www.uark.edu/campus-resources/cotinus/.