It has been called (among other things) “the weed from hell.” And it could be heading your way. Maybe not tomorrow, or this year — but sooner or later.
It's called cogongrass, and you may never have heard of it. Nurseries and garden centers sell a hybrid version of the plant as Japanese bloodgrass, and it can be a quite attractive addition to the landscape, with its reddish leaves and feathery fronds.
But weed scientists believe that even the hybrid, under the right conditions, can revert to the invasive form, which can gobble up real estate like PacMan scarfing up electronic ghosts. Growing 2 to 4 feet in height, it displaces native vegetation, desirable pasture grasses, and young trees. It has almost no nutritional value for livestock and its high flammability can create wildfire hazards.
It is already established in large areas of Alabama, Louisiana, and Mississippi, where agriculture officials are cranking up an offensive against the plant to keep it from becoming another kudzu — the vine originally brought to the South as a cure for erosion that, with its voracious foot-per-day growth rate, ended up gobbling virtually anything in its path: trees, houses, telephone poles, radio towers (and the joke was that if you sat still in one place very long, it'd get you, too).
Weed scientists, on their Top 10 List, rank cogongrass as the seventh most noxious plant in the world. The “worst” list varies from state to state, but the plants nearly all have in common that (1) they're not native to the United States, (2) they were brought in mostly accidentally, but sometimes to serve a specific purpose (as with kudzu), (3) they spread easily and quickly, and (4) they have no, or very limited, natural enemies.
Chinese privet, for example, was introduced into the South in the mid-1800s as an ornamental hedge. Now it's choking out woodlands everywhere and birds drop its multitudinous seeds all over creation.
Others such as water hyacinth and Chinese tallow tree (popcorn tree) were mostly nuisances in coastal areas of warmer winters, but in recent years have been adapting and moving steadily northward. Johnsongrass, a Mediterranean region native, was introduced to the United States as a forage plant in the 1800s and farmers have waged war against it for decades.
Cogongrass, like johnsongrass, is a perennial that spreads by rhizomes. Chop up the rhizomes by cultivation and, voila, they just make more plants. Rhizomes that cling to equipment can be transported to new areas to establish yet another beachhead.
Unlike kudzu, which can be controlled with determination and several applications of Roundup, experts say once cogongrass takes root, Roundup won't completely kill it. A multi-year effort, involving Roundup, burning, disking, and Arsenal, is recommended — and in the process, some trees on forest lands may be lost.
The Mississippi legislature is being asked to fund a program to try to stop the northward march of the plant, now already past Interstate 20. But as in most other states, money's tight, so who knows?