Published on 05/09/06

Green industry grappling with nonnative invaders

By Stephanie Schupska
University of Georgia

Not all nonnative plants are invasive. In fact, for every 100 foreign plant species, only one becomes a problem. But that 1 percent worries the Georgia plant industry.

Controlling “nonnative, invasive pest plants in natural environments is one of the most sensitive and volatile issues being debated today” by the plant, or green, industry, said Gary Wade, a University of Georgia Cooperative Extension horticulturist.

Ornamental horticulture includes greenhouses, container nurseries, turfgrass and field nurseries. It brought in a farm- gate value of more than $650 million in Georgia in 2004. And one of its representative organizations, the Georgia Green Industry Association, is approaching the invasive plant problem head-on.

The GGIA formed an invasive plant task force in 2003 that is examining the issue and moving toward better solutions. Even so, they have to deal with the issues that make an invasive plant popular in the first place.

“Ironically, many of the characteristics that make invasive plants invasive are the same ones that make them appealing as landscape plants,” said Wade, who co-chairs the GGIA invasive plant task force. “They’re tough, adaptable, quite ornamental and easy to propagate.”

The task force assigned plants to three categories based on their degree of invasiveness and then looked at which ones are available in the nursery trade.

Plants in category 1 have a serious impact on native environments and displace native plant species over a wide area. These include mimosa, Chinese privet, multiflora rose, Japanese climbing fern, Chinese tallow tree, autumn olive, Japanese honeysuckle and kudzu.

Category 2 plants have a moderate impact on native environments. Their population is localized, not widespread like that of a category 1 plant. But they’re harming native plant communities. Examples are Chinese and Japanese wisteria, princess tree and bigleaf periwinkle.

Category 3 or “watch list” plants have the potential to be invasive but aren’t invading native plant communities. Examples are lacebark elm and burning bush euonymus.

Invasive plants compete with native species for light, water and nutrients. They also change the structure of a community’s vegetation and decrease food sources and protective cover for wildlife. Perhaps the most noticeable effect on the environment is that they simply make an area look worse and hinder access to recreational sites.

The Georgia green industry is combating the issue through research, surveys and education. They’re finding out just how big the invasive plant problem is.

In the fall of 2005, the GGIA surveyed all growers, landscapers and plant dealers in Georgia. Completed survey results showed that all category 1 plants, which are the most invasive, are occasionally being sold.

However, an overwhelming majority of those who responded said they would welcome regulating help from GGIA. Of the respondents, 74 percent said, “Yes, the GGIA should regulate the production, sale and installation of invasive plants.”

“Georgia’s green industry wants to be a part of the solution, not a part of the problem,” Wade said.

Wade outlined the group’s plan of action.

First, they’re working to help manage invasive plants already in Georgia. Then they want to phase invaders, particularly the category 1 plants, out of the trade. At the same time, they plant to educate their industry and the public about invasive plants.

Last, but not least, they want to develop a way to assess new plant introductions for their invasive potential before the plants make their way to market, preventing future invaders.

Wade lists three ways anyone can help with this problem:

1. Don’t plant invasive plants in your landscape.

2. Help educate others in your community about invasive plants.

3. Volunteer to help manage invasive plants in your community.

To learn more about invasive exotic pest plants in Georgia, visit the Georgia Exotic Pest Plant Council’s Web site at

(Stephanie Schupska is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)

Stephanie Schupska is the communications coordinator with the University of Georgia Honors College.