Broad-leaved Helleborine (Epipactis helleborine) is an invasive woodland orchid native to Europe. It was introduced to the United States as an ornamental plant and has been present in New York State since the 1870s.
A single plant can produce thousands of seeds that have high growth rates which allows Broad-leaved Helleborine to easily take over the areas they inhabit. Broad-leaved Helleborine is a monocot plant that forms from a system of rhizomes. Due to this, more than one stem can be produced from the same root system. Unlike most orchids that grow in trees, Broad-leaved Helleborine grows in soil and can be found on roadsides and disturbed areas.
Plants can grow up to 3 feet tall. Leaves are oval to lance-shaped and grow alternately along light green stems that are covered with short hairs. Flowers appear in NY in July and August, they range from pale yellow to green or pink in color and form in clusters along the top of the stem.
Controlling efforts can be difficult. It is important to choose a method that will be most efficient and the correct herbicide, if needed.
The most efficient time to pull these plants is when they first flower since the roots and rhizomes are at their weakest. You must remove the entire root system and all of its rhizomes.
Typical lawn herbicides like 2,4-D and dicamba do not work to manage this species since they target dicots, not monocots like helleborine. Using the herbicide active ingredient, sulfentrazone, to spot-treat the plant is found to be most effective. It is best to cut the plant and then apply the treatment. All herbicides should be applied according to label instructions.
Identification photos provided by Michigan State University MSU Extension
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Angela Tenney and Erin Hill, M. S. U. (2023, June 19). Broadleaf Helleborine: A weedy orchid invading lawns and flowerbeds. Gardening in Michigan. https://www.canr.msu.edu/news/homeowners_battling_a_weedy_orchid_invading_lawns_and_flowerbeds#:~:text=For%20a%20few%20helleborine%20plants,Weed%20%26%20Grass%20Killer%20Concentrate)
Wildflowers of the Adirondacks: Helleborine (Epipactis Helleborine). Adirondack Wildflowers: Helleborine | Epipactis helleborine. (n.d.). https://wildadirondacks.org/adirondack-wildflowers-helleborine-epipactis-helleborine.html