By Elaine Mills, Extension Master Gardener
Glechoma hederacea (ground ivy), also known as creeping Charlie and gill-over-the-ground, is listed as invasive in both Arlington County and the City of Alexandria and has been reported in national parks in Maryland, Virginia, Washington, D. C., West Virginia, and Tennessee. A European native plant, this herbaceous perennial was brought to North America by early settlers as a medicinal plant for skin and internal ailments.
Ground ivy is member of the mint family with square stems, two-lipped bluish-purple flowers, and pairs of leaves at each node. Its leaves are rounded to kidney-shaped with scalloped margins and have a distinct minty odor when crushed. The plant creeps over the soil surface by means of stolons, forming a thick mat and crowding out native plants when it invades roadsides, pastures, orchards, and open woods. It is considered especially troublesome as a weed in lawns.
Ground ivy colonizes most frequently by producing adventitious roots at each node, allowing it to spread up to 30 inches. It spreads less frequently by seeding, but seeds that are produced shortly after flowering from March through June can begin germination immediately. The plant may have several other advantages over its competition. Although it prefers damp, shady areas, it can tolerate full sun and remains green over the winter unless frost is too severe. It may also suppress the growth of surrounding plants through allelopathy, the production of chemicals that reduce seed germination and root and shoot growth.
Once established, ground ivy is challenging to control because of the difficulty in completely removing all root and stolon fragments. Seed banks may also remain viable for some time. Mechanical and chemical control methods are usually recommended, and a rust fungus is being studied as a possible biological control. For detailed information on cultural control of ground ivy in lawns, see “Creeping Charlie: Management and Value to Pollinators” from the University of Minnesota.
Sources:
- Chandran, Rakesh . “Ground Ivy.” 2018. West Virginia University Extension Service
https://extension.wvu.edu/lawn-gardening-pests/weeds/ground-ivy - “Ground ivy.” University of Maryland Extension
https://extension.umd.edu/hgic/topics/ground-ivy - “Weeds: Glechoma hederacea.” Virginia Tech.
https://weedid.cals.vt.edu/weedimg/264 - Wolfin, James and Phoebe Koenig. “Creeping Charlie: Management and Value to Pollinators.” 2017. University of Minnesota.
https://turf.umn.edu/news/creeping-charlie-management-and-value-pollinators