Heaven help you if you have it in your yard. If? What am I saying? It’s everywhere! Garlic Mustard, Alliaria Petiolata, looks benign enough. A member of the brassica family, it has button-like clusters of small white flowers atop stalks up to 3 1/2 feet tall. The leaves are nearly heart-shaped, toothed and wrinkly. The ones in my yard seem rather more rounded than heart-shaped, but so it often is with intruders. They come disguised. But not enough to be obvious that they are out to get you.
What could be so bad about a plant that conjures up thoughts of viniagrette and aromatic pairings with onions? The leaves even faintly smell of garlic when crushed, to my mind a pleasurable reminder of good meals. Hence the name, garlic mustard, but it’s a menace. Introduced from Europe in the 1800′s, it crowds out native species in a twinkling, creating huge monocultural meadows of nothing but garlic mustard. By reducing biodiversity, the area becomes inhospitable to native plants and animals, eliminating regular foods and shelter areas. Introduction of non-native species is a top cause of habitat destruction and native species extinction.
America has always welcomed immigrants. It’s what we’re all about. The problem is, new arrivals bring the living genome of the old country right along with them. It all started with the Pilgrims and probably even before. From Europe and beyond, bugs, seeds, vertebrates and invertabrates washed up on our shores along with the huddled masses. And while humans assimilated and made up the crazy quilt of american culture, plants and animals sometimes went rogue.
Many species accidentally introduced to a new habitat don’t make it. It’s too hot, too cold, the food is all wrong and like a disgruntled tourist they just slope off. Others, often species that aren’t too choosy, put their feet up and stay awhile. Alot of those can become a gentle part of the scenery, like the European Cabbage White Butterfly, the ubiquitous white butterfly found nearly everywhere in the New World, but originally an Old World species.
The third category are the troublemakers. They thrive anywhere, eat every food, like the heat, the cold, the damp, the dry. They are like noisy neighbors who plop themselves down in the middle of everything, reproduce like crazy and monopolize the neighborhood. Nothing bothers them and they never go away. And all their relatives come to stay.
Which brings us to garlic mustard. Plant bulletins describe it as an invasive exotic, an invader of woodland habitats, a threat to spring ephemeral wildflowers like spring beauty, trillium and trout lilies. Research points out damage to biodiversity (it kills everything else around it) and forest health. It is thought to be one of the most potententially harmful and difficult to control invasives anywhere. Studies show it actually changes the health of soil where it grows, poisoning it from supporting any other life. It’s like science fiction! But it’s real.
What to do? Pull it up by the root! Have a pulling party! Haul it out of the ground by the fistful and add it to the garbage, or burn it the next time you have a barbecue. Whatever you do, don’t add it to the compost pile. The seeds will wind up in your garden and you will spend the rest of your life trying to eradicate them.
There isn’t any way to stop organisms from traveling from place to place. The Pilgrims brought them in with grain seeds, and on their shoes. Freighters bring them in their balast, airplanes in their wheel wells. This happened with the Brown Treesnake, introduced to Guam during World War ll by military transport. The snake extirpated most of the birds on the island, and is now working its way through the populations of small mammals. Frightening but true.
Do we have Garlic Mustard at Hill-Stead? Absolutely. We are no different than any other outdoor area. Invasives are everywhere. Science is making advances toward learning how to rebalance things. Meantime, familiarize yourself with the look of the plant, and yank it up any time you see it. I promise not to scold you for picking the wildflowers.
See you on the trails,
Diane Tucker, Estate Naturalist