UF/IFAS Okeechobee County Extension Service

458 Highway 98 North

Okeechobee, FL 34972-2578

Phone: (863) 763-6469

E- mail: dfculbert@ifas.ufl.edu

August 13, 2003

Feature Article - for release the week of August 18, 2003

Dan Culbert - Extension Horticulture Agent

Thousands of different plants can be grown in our Florida Yards, but a few of the common plants grown locally are disasters that are waiting to happen. Some of these plants can escape, and become "biological pollutants" that threaten natural areas. Information for today's column comes from UF Extension Specialist Dr. Ken Langeland and from the Florida Exotic Plant Pest Council.

There are several words that are commonly used to describe and classify these plants. First off, a weed is a plant out of place. Bermudagrass in a St. Augustinegrass lawn would be a weed to a landscaper but may be perfectly acceptable to some homeowners. So, one man's weed may be another's lawn.

The plants we are discussing in this column are called invasive, which means they can take over areas where they never grew before. They are survivors that can tolerate poor growing conditions, can repel or put up with local pests (or don't have any at all), and often can out-grow other plants in the race to capture light, water, and plant nutrients.

Most all of these horrors are non-natives, i.e., they came from somewhere else. These plants may also be called exotic, but this word is generally used with plants that have more desirable characteristics.

Many of the better adapted plants are Florida natives - those plants that were in the area before the onset of European civilization. Be careful of the term native: the Black Olive tree is a Florida native, coming from the Florida Keys. But, it is too sensitive to freezing temperatures to be used locally.

A prohibited plant is one that, by law can not be grown in a particular area. Several kinds of prohibitions exist. The Florida Department of Environmental Protection lists fifteen plants as prohibited. In parks and other natural areas, the state is removing Australian Pines, Brazilian Peppers and many invasive aquatic weeds that choke our canals and lakes. When they issue a permit for various land activities, they "encourage" the private landowner to do the same.

The US Department of Agriculture and our Florida Department of Agriculture maintain a list of noxious weeds, of which 18 are known to grow in Florida. These plants generally cause a disruption to commerce. A common invader to our area, the Tropical Soda Apple, is spread when cattle feed on the fruit, and seed are deposited in animal waste when moved to new pastures. When seed or nursery plants are sold, they must be tested or inspected, and then certified as free of noxious weeds like Cogongrass or Air potato.

A final term used is undesirable, and may be included on lists of plants developed by local governments. These plants may be discouraged because they perform poorly in local conditions. Locally, the weak-wooded Chinaberry and the shallow rooted Norfolk Island Pine can present a danger, especially in windstorms. The exotic and fruitful Surinam Cherry can serve as a host plant for the Caribbean Fruit Fly, and in citrus growing areas may be prohibited.

THE EPPC LIST

Professional land managers and scientists that deal with unwanted vegetation in Florida have an organization that studies invasive and works towards reducing their effects on public lands. They have studied these plants' behaviors and have developed a list of invasive plants based on how serious their threat is to Florida's natural areas. Two groupings have been developed:

Category I are species that are invading and disrupting native plant communities in Florida. This definition relies on the documented ecological damage caused. There are 10 of these Category I plants that have been documented in our county, plus another dozen or so that have been seen here but not yet documented by EPPC.

Category II are species that show a potential to disrupt native plant communities. These species may become ranked as Category I, but have not yet demonstrated disruption of natural Florida communities. The list names 66 plants found in Okeechobee county, and includes some plants that are available in nurseries and garden centers.

The EPPC List is revised regularly, and is posted on the Internet, along with other information dealing with invasive plants and horticultural horrors: http://www.fleppc.org/ . The University of Florida has placed an excellent reference manual edited by Drs. Langeland and & K. Craddock Burks on the Center for Aquatic and Invasive Plant website: Identification & Biology of Non-Native Plants in Florida's Natural Areas. You can see a copy of this book at our Extension office or purchase it though bookstores and the UF/IFAS publications office.

If you need additional information how to identify or manage invasive weeds, call or stop by our office at 458 Hwy 98 North. Our phone number is 863-763-6469, and you can email us at okeechobee@ifas.ufl.edu.

Trade names, where used, are given for the purpose of providing specific information. They do not constitute an endorsement or guarantee of products named, nor does it imply criticism of products not named. The Florida Cooperative Extension Service - Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational information, and other services to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin. Florida Cooperative Extension Service / IFAS /University of Florida. Christine T. Waddill, Dean.