Are you one of the many landowners realizing, in horror, that you have the dreaded goutweed?
We moved into our house a few years ago. At that time, I noticed a couple of patches of a lush-looking plant, but since it was the fall, I paid it little attention. The following spring, before any other plants started growing, I saw the green carpet emerging.
(Photo courtesy of the Adirondack Park Invasive Plant Program)
Having learned about goutweed, I grew nervous that this plant now plagued our property, too. When flowers appeared, it was confirmed - I had goutweed. Talking with friends and neighbors, I came to learn that we all had it. Now we swap strategies to get rid of it.
Treatment methods vary, depending on the size of the infestation and the creativity of the landowner. Some dig it out, roots and all. Some cover it with cardboard. Others try layering newspaper. One even tried smothering it with old carpet. Others resort to stronger means, using the herbicide glyphosate. I found a combination works best and that, if pulling, it is critical to remove as many of the hair-like roots as possible before adding layered paper and mulch.
Whether pulling, papering, or spraying, your patience and persistence are required when managing this vigorous plant.
Goutweed (Aegopodium podagraria), also known as bishop's-weed and snow-on-the-mountain, is an herbaceous perennial. Native to Europe and Asia, it was introduced as an ornamental and was well established in the United States by the late 1800s. Two varieties are common: a solid green form and a variegated form that has bluish-green leaves with creamy white edges. The green variety appears to be the more invasive one.
Goutweed grows in sunny and shady areas but thrives in moist soil and in light to moderate shade. The leaves are divided into three groups of three leaflets. The leaflets are toothed and sometimes irregularly lobed. It produces small, white, five-petaled flowers in mid-summer. The flowers are arranged in flat-topped clusters held above the ground on a leafy stem up to 3 feet tall.
What makes goutweed problematic is that it is a fast and aggressive spreader that forms dense, thick patches. It spreads mainly by vegetative means and has fine, hair-like rhizomes that are long, white and branching. Its botanical name means "little goat feet" because plants have a tendency to run through the garden, out of control, using roots that ramble like little running feet. Plants choke out other ground-layer plants and can spread into natural areas, inhibiting the establishment of conifers and other native tree species.
Goutweed is still sold at nurseries, though mostly the variegated form, but it can also hitchhike on other nursery stock. I once noticed small sprigs of goutweed growing in a potted native fern I was thinking of buying. It is common in many yards, so it can also be transported unintentionally during plant swaps.
If your garden design includes goutweed, nurseries recommend planting it in a container in the ground or where solid edging can help regulate its spread.
If you are up to the task of management, remember never to compost this plant. Put it in trash bags and take it to the transfer station. Be sure to monitor the site for several years, too. That's the challenge with invasive species; they keep coming back.
'Eye on Invasives' is a biweekly column that spotlights a top invader when it is easiest to identify. The Adirondack Park Invasive Plant Program is a partnership program housed at the Adirondack Chapter of The Nature Conservancy in Keene Valley. Find out more about this award-winning program online at www.adkinvasives.com.