Common names: Ground ivy, gill-over-the-ground, creeping Charlie, field balm, haymaids, cat’s foot, alehoffs
Latin name: Glechoma hederacea L.
Family: Lamiaceae (Mint Family)
General Description and Identification
Ground ivy is a perennial herbaceous plant that creeps along the soil surface and thrives in moist and shady areas (Figure 1). It was introduced to the US from Europe in the 1600s. Although mostly found in turf and landscape settings, ground ivy can be problematic in some vegetable production settings, including along mowed field edges and in and around high tunnels. Ground ivy does not represent much of a threat for large-seeded and upright crops. However, ground ivy can “crowd out” and shade smaller statured vegetable crops and those that require more time to establish. It spreads vegetatively through its long stems that form roots at their nodes, as well as by stolons and rhizomes.
Figure 1. Ground ivy forms a thick mat of kidney-shaped leaves (Photo by S.L. Meyers).
Ground ivy can be identified by its:
- Square stems.
- 1-inch kidney-shaped leaves with scalloped margins. These leaves appear on long petioles in pairs on either side of the stem (opposite leaf arrangement) and give off a distinctively foul odor when crushed or mowed.
- Lavender flowers with magenta dots (Figure 2). Flowers are tubular, ½ to ¾ inch in length, and appear in clusters of 2 or more between March and July.
- Its dark brown fruits (“nutlets”).
Figure 2. Ground ivy flowers (Photo by A.J. Patton).
Because it shares the mint family with numerous other weeds, ground ivy can be confused with weeds like henbit (Weed Spotlight: Henbit | Purdue University Vegetable Crops Hotline (vegcropshotline.org)) and purple deadnettle (Weed Spotlight: Purple Deadnettle | Purdue University Vegetable Crops Hotline (vegcropshotline.org)). It can also be confused with creeping Jenny (Lysimachia nummularia), which has a similar growth habit and an opposite leaf arrangement. However, creeping Jenny leaves are round and it’s flowers are bright yellow (Figure 3).
Figure 3. Creeping Jenny grows along a field edge in Indiana (Photo by S.L. Meyers).
Control Methods
- Ensure adequate field drainage to limit the moist environment that favors ground ivy establishment and growth.
- Rotate to crops or cover crops that overtop ground ivy and outcompete it for light, such as sweet corn and pumpkins.
- Herbicide control can be variable. Starane Ultra (fluroxypyr) can be an effective option and 2,4-D and glyphosate may provide some suppression. There is evidence to show that applications made in the fall can be effective. Visit the Midwest Vegetable Production Guide (mwveguide.org) for herbicides registered for use in the crop you grow.
- Small patches of ground ivy can be pulled by hand or shovel, ensuring that all plant parts are removed from the field.
“Fun Fact”
- Ground ivy is poisonous to horses if eaten in large amounts.
Literature cited
- Weeds gone wild. Alien plant invaders of natural areas. Ground ivy. https://www.invasive.org/alien/pubs/midatlantic/glhe.htm
- Pamela L.S. Pavek, USDA NRCS Plant Materials Center, Pullman, Washington. Ground Ivy. https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_glhe2.pdf
- Minnesota wildflowers. A field guide to the flora of Minnesota. https://www.minnesotawildflowers.info/flower/ground-ivy
- Fresenburg, Brad. Turfgrass and weeds (2008). https://mospace.umsystem.edu/xmlui/handle/10355/51724