Wild parsnips: One of the most tenacious invasive plants
Wild parsnip is a floral Dorian Gray, an invasive, venomous plant that masquerades as a good-looking flowering plant of American roadsides and fields.
It鈥檚 not the only botanical wolf in sheep鈥檚 clothing 鈥� comes immediately to mind 鈥� but it may be the nastiest.
A widespread nuisance
Introduced as by European settlers in the 17th century, it jumped the fences of colonial gardens and now grows nearly everywhere. Only Florida, Georgia, Alabama, Mississippi, and Hawaii , according to the U.S. Department of Agriculture National Resources Conservation Service.
That census dates to 2007, so it may be in all 50 states by now.
The belligerent ability of wild parsnip to spread and push out native plants is one reason that it's so nasty. The other is that the plant鈥檚 leaves, stems, and flowers contain chemicals called furocoumarins that, in the presence of sunlight, cause blistering.
Plants 'burn' the skin
Technically it鈥檚 known as . In everyday language, it鈥檚 a painful burn with sores and skin discoloration that may last a year or longer.
Wild parsnip plants, which have long, thick taproots, are , which means that they behave somewhat like a biennial. They produce a low rosette of leaves for at least the first year; then, when conditions are just right, they produce a flowering plant, set seeds, and die.
Like Queen Ann鈥檚 lace and other cousins in the carrot family, their flat, umbrellalike flower clusters are held on a single, stiff stalk than can grow four feet and taller.
Methods for control
Like many exotic plants, wild parsnip is aggressive once begins to spread, nearly impossible to stop. Parts of my Vermont acreage already are covered, far too many plants to try to remove by hand or by spot spraying with or an organic herbicide.
I鈥檇 rather not resort to chemicals, so next spring I鈥檒l be in our field with a brush cutter, wearing long sleeves and long pants, mowing and remowing so that plants don鈥檛 have a chance to flower and set seeds.
I鈥檒l need to return the next spring and summer, and the next, and the next. I suspect it鈥檚 a losing battle, but one I want to wage.
-----
Karan Davis Cutler blogs regularly at Diggin鈥� It. To read more, click here. She's a former magazine editor and newspaper columnist and the author of scores of garden articles and more than a dozen books, including 鈥淏urpee - The Complete Flower Gardener鈥� and 鈥淗erb Gardening for Dummies.鈥� Karan now struggles to garden in the unyieldingly dense clay of Addison County, Vt., on the shore of Lake Champlain, where she is working on a book about gardening to attract birds and other wildlife.
