CHARLESTON, W.Va. -- A recent trip to New Orleans brought home an important fact about gardening. Every ecosystem deals with invasive plants.
To quote an article by the University of Florida extension service, "When plants grow where they are not wanted, we call them weeds. To homeowners, weeds may be unwanted plants in lawns or gardens. To farmers, weeds are plants that interfere with raising crops or livestock. To biologists who manage natural areas, weeds are plants that interfere with the functions of natural communities."
The park rangers who led our tour of the Jean Lafitte National Historical Park's Barataria Preserve near New Orleans continually pointed out nonnative species that were taking over the marshes and swamps of the delta area.
Giant salvinia from South America was thick on top of the waters between the natural levees in this 20,000-acre preserve. Jim McDonald, our tour guide from the National Park Service, said the free-floating aquatic fern was brought from Brazil as a decorative plant for home water gardens and aquariums and has met no natural predators. Scientists are working to develop a weevil that eats the plant and no other plants, but that process is slow. This aggressive menace flourishes in Louisiana's warm, fertile waters and can cover large areas in just a few weeks.
A vine that looped through the trees of the preserve, Dioscorea bulbifera, is nicknamed the "air potato." This one is a pest throughout warm climates, landing on the invasives list in Florida, Texas, Hawaii and other states. McDonald told us it's harder to eliminate than kudzu. Chinese tallow (said to be brought to America by Ben Franklin), alligator weed and water hyacinths are all invasive in the bayou, having been brought in from other areas and facing no known predators.
What does this have to do with West Virginia gardening? If a plant is considered invasive in one area, there is a chance it can become invasive in another. And that's why using native plants is the best bet when planting a garden in our area.
The most important trees in the bayou were the deciduous bald cypress and the Nyssa sylvatica biflora, or swamp tupelo. I was with a group of teens, and while the trees were of some interest to them, the spiders spinning webs above the nature trails brought many more verbal responses! There are literally thousands of these eight-legged creatures. Everywhere you turn there's a web, creating a canopy above the nature trail. We were told they are golden silk, zipper and crab spiders, all nonpoisonous -- but that didn't make them any less creepy.