Weeds and Exotic Pest Plants

 Tens of thousands of species of plants have been moved from one part of the world to other parts to be cultivated for food, timber, livestock forage, their ornamental value and other purposes. Most of these plants are well-behaved. They serve their functions and cause no trouble. Some, however, escape from their farms and gardens and invade surrounding natural environments. The worst of these plants spread rapidly, compete with the native plants and change entire ecosystems. This comparatively small group is known as exotic pest plants. These exotic plants have few to no natural predators or diseases so they have an advantage over the native plants. As they overwhelm native plant populations, the native animals that depend on the natural ecosystems for food and shelter begin to disappear as well.

     Florida has a large number of exotic pest plants. The Florida Exotic Pest Plant Council monitors these plants and maintains a list of them on their website. The control of these pests costs taxpayers millions of dollars annually. University of North Florida Grounds staff has removed nandina, Lantana camara and sprengeri fern from the landscape. Trees like camphor tree, tallow tree and mimosa are among the worst of the pest plants in the natural areas of the UNF campus. The staff work to control these trees and other exotic pest plants, too, including air potato, Hall’s honeysuckle, cogon grass, Chinese privet, water hyacinth and water spangles.

     This does not mean that all non-native plants are bad. You need not cut down your orange tree or stop growing tomatoes and azaleas. However, all of us should be aware of the problem and help work to control the bad plants. You can do this in your own backyard or volunteer to help parks with the problem. Review the lists at the Florida Exotic Pest Plant Council’s website so you know what to remove from your landscape or avoid. If you wish to participate more actively, contact the First Coast Invasive Working Group.

Examples of Exotics in the Preserve

Cogongrass (Imperata cylindrica) © Chuck Hubbuch
Chinese tallowtree (Sapium sebiferum)
Chinaberrytree (Melia azedarach) © Chuck Hubbuch