5 Beware Bamboo!
Once a stand of this fast-growing, hearty plant takes hold, it can be nearly impossible to stop its spread. What most people don’t realize is that bamboo is technically a grass, and as such it is a plant that knows how to spread. Left unchecked, in fact, bamboo will spread indefinitely, taking root wherever there’s enough soil for its complex network of roots. The difference between bamboo and other grass species is that bamboo can grow dozens of feet high and thicker than a man’s arm.
4 Alternanthera Philoxeroides
The scientific name “Alternanthera philoxeroides” might not sound all that threatening, but the plant’s common name, alligator weed, gives you a better sense of what this “noxious” perennial weed does: Just like its namesake alligator, it is an aquatic killing machine. Especially is the western coastal states, alligator weed can take hold in rivers, streams and lakes, growing quickly and forming floating mats atop the water that strangle other plants and block access to light and air, hurting both florae and faunae.
Ever so technically, algae are not plants. The term refers more to a collective of living things, as each alga is a single-celled or multicellular organism. But it behaves like a plant, dammit, and it can be wildly invasive and destructive. In fact, algae “blooms” are what have led to various aquatic “dead zones,” such as the region in the Gulf of Mexico practically devoid of animal life. This is because the algae cells consume so much of the dissolved oxygen in a given part of the sea that there is not enough left to support other life. Of course, we can’t really blame the little alga: It’s runoff from farms that fuels their colonial expansion in the first place.
Stinkweed, AKA stinkwort, is just a wonderfully named, highly invasive weed. If you look at any given empty lot, field, pasture or untamed meadow, it’s likely full of this sticky, not-so-pretty weed. But stinkweed doesn’t often kill off other species; it just takes up residence wherever it can. Its biggest offenses are being ugly, pungent and rather sticky. But we can forgive all that because, again, it’s named stinkweed/stinkwort.
1 Russian Olive and Autumn Olive Plants
The consensus among farmers, gardeners and horticulturists seems to be that America’s most hated non-native invasive plant species is a tie between Russian olive and Autumn olive plants (neither of which have anything to do with the olives you eat, which are from trees). These plants grow quickly and thickly, and they change the soil chemistry where they take root, so not only do they choke out native plants, they also ruin the plants’ chances of ever-growing back. And birds love their little fruits, so the olive plants’ seeds get spread far and wide.