Published on 04/24/03

Creating new plant varieties a long process

By Sharon Omahen
University of Georgia

Among the garden set, a new plant variety is almost as exciting as a new baby's arrival. After all, a new plant is a new baby of sorts. What most home gardeners don't know, though, is how long that new "baby" took to be born.

Carol Robacker, a horticulturist with the University of Georgia, has been working for the past seven years to breed a new azalea variety resistant to lace bugs. Azalea lace bugs are major pests of azaleas.

"We've found resistance in wild plants," she said. "But to combine that quality into a plant that's attractive to consumers isn't easy. From seed to flowering takes about three years. And the cycle has to be repeated several times to obtain our goals."

Less pesticides, more appeal

A resistant plant would reduce the amount of pesticides homeowners and landscapers apply, and the new variety would look better and live longer.

"Though it's important to develop pest-resistant cultivars, breeding for pest resistance is usually much more difficult than breeding for aesthetic qualities," Robacker said.

As a plant breeder working with the UGA College of Agricultural and Environmental Sciences, Robacker focuses her breeding efforts on woody ornamental plants in home and commercial landscapes.

Besides the azalea project, she's working on new abelia varieties. Abelia is a hedge-type shrub typically used for foundation planting around commercial buildings and homes.

"Consumers want an abelia that's smaller and more compact; has brightly colored flowers, year-round appeal and attractive foliage; and is cold-tolerant and heat-, drought- and pest-resistant," Robacker said. "Basically, they want the perfect plant. And they want it in a cute, little, meatball shape."

Breeding a "perfect" plant is probably impossible. But by making the right crosses and growing enough seedlings, scientists often come up with improved cultivars, she said.

"Ideally, these cultivars should be evaluated over several years and locations," she said, "to determine their adaptability to heat, drought and cold, and to improve the chance of detecting any pest problems."

You can't rush and release too soon

For the past three years, Robacker has been evaluating a new tree variety for a northern grower.

"It's a beautiful tree with silver leaves," she said. "The first two years, it looked great in our Southern climate. But the third year, all my specimens developed disease. If the tree had been released after the second year of evaluation, consumers wouldn't have been happy with the long-term results."

Robacker's new abelia varieties will head to commercial nurseries for evaluation this summer. They should be released to the public in two years. That is, if they pass her high standards.

Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.