The carrotwood tree growing in your back yard provides deep shade and is so robust, it doesn't need much TLC but an occasional pruning. The same goes for the Chinese tallow that grows in leaps and bounds and the Brazilian pepper that produces those pretty red berries just in time for the holidays. Lush green ferns of every sort fill spaces where nothing else would grow. • You're thinking your landscape is pretty spiffy, but here's the shocker: Your yard is an eco nightmare that's killing Florida's natural areas and wildlife habitats. Your turbo-charged, mile-a-minute growers are so adept at survival, they're overtaking, displacing and destroying native species and their habitats. Not to mention they're illegal.
One of the most well-known noxious plants is kudzu. Farmers were encouraged to plant the exotic vine with fragrant purple flowers for erosion control in the 1930s. The climbing vine went wild — it grows a foot a day — and now covers 2 million acres of forest in the South, including northern Florida. Just take a drive on Interstate 75 and you'll see bright green kudzu blanketing trees, utility poles and anything else that gets in its way. The invasive plant, which develops massive tap roots weighing in at 400 pounds or more, is banned by the U.S. Department of Agriculture, and countless millions have been spent trying to control and remove it.
But kudzu almost looks tame compared with cogongrass, which is overtaking natural areas and roadways in Florida. "It's one of the 10 worst weeds in the world," says William T. Haller, Ph.D., acting director of the Center for Aquatic and Invasive Plants in Gainesville. Like kudzu, the African native was imported for erosion control along highways. But after 80 years in use, the fast-spreading plant has seriously altered natural areas. Even worse, it's impossible to kill, Haller says.
Back to your yard. You might not have cogongrass or kudzu, but there are scores of other invasive plants that can easily engulf your landscape — and take your neighborhood and other areas with it. Plants such as air potato vine, winged yam, Japanese climbing fern and Old World climbing fern can grow out of control, wrapping around other plants and stealing the sunlight they need to live. They can end up in your neighbor's yard or a nearby park when their seeds and spores are spread by the wind.
Some invasives produce seeds and berries that are eaten by birds and mammals, who digest them and then deposit the still-viable seeds in droppings on other properties near and far. That's how Brazilian pepper has infested 700 acres in Florida, where its dense shade canopy kills other plants.
Invasive plants can do their dirty work underground, too. With massive underground root systems (think kudzu), they take hold of large expanses and send up "volunteer" plants. Australian pines spread this way, too.
We can even lay part of the blame on Mother Nature. Hurricanes and tropical storms help spread seeds, berries and spores (and plant diseases) from one end of the state to the other.
Federal and state laws prohibit the sale and use of noxious weeds, including carrotwood, Chinese tallow, Brazilian pepper and melaleuca (see accompanying list). You shouldn't find them at garden centers or plant fairs, but that doesn't mean they aren't in circulation. You might receive a cutting from a well-intentioned but ill-informed friend or neighbor. You might even be breaking a federal or state law by growing one or more in your yard, although it's unlikely law enforcement will come calling.
"There are no plant cops that go wandering around looking for illegal plants. But if you start selling carrotwood, you are going to get in trouble," says Haller.
Ridding the state of invasives is a mighty task, especially if homeowners don't cooperate, experts say. Many homeowners don't understand the magnitude of the problem or how all properties are essentially linked, says Ken Langeland, professor of weed science at the University of Florida in Gainesville.
"The situation is getting worse," Haller adds. "We have a lot of people moving plants, a bigger population and a lot of people interested in different, weird plants. We can't predict or know which plants are going to become a problem or not."
Yvonne Swanson is freelance writer in St. Petersburg. Contact her at [email protected]