Invasive Plant Species Control
Garlic Mustard
(Alliaria petiolata)
Native Substitutes:
- Rue-anemone (Anemonella thalictroides)
- Cut-leaved toothwort (Dentaria laciniata)
- Bloodroot (Sanguinaria canadensis)
- Wild ginger (Asarum canadense)
Description
Appearance: Biennial forb with weak single stems 12-36" high in its second and flowering year. Only plant of this height blooming white in wooded environments in May.
Leaves: Round, scallop-edged, dark green; first year, rosettes of 3 or 4 leaves; second year plants have alternate stem leaves. Leaves and stems smell like onion or garlic when crushed.
Flower: White, small and numerous, with four separate petals. Each plant has one or two flowering stems on second year plants. Seeds are contained in slender capsules 1-2 1/2" long containing a single row of oblong black seeds.
Seeds: Viable in the soil for 5 years.
Root: White, slender taproot, "S"-shaped at the top.
Ecological Threat
Garlic mustard spreads into high quality woodlands and upland and floodplain forests, not just into disturbed areas. Invaded sites undergo a decline of native herbaceous cover within 10 years. Garlic mustard alters habitat suitability for native insects and thereby birds and mammals. This European exotic occurs now in 27 midwestern and northeastern states and in Canada.
Legal Status: This plant is a prohibited noxious weed in Minnesota and must be controlled or eradicated as required by Minnesota Statutes, section 18.78.
Control Methods
| Mechanical | Chemical | Biological |
|---|---|---|
| Pulling in areas of light infestations | Spot application of 2% glyphosate in early spring or late fall when native plants are dormant | Research in progress |
| Flowering stem cutting at ground level |
Sources
Wisconsin Manual of Control Recommendations for Ecologically Invasive Plants, 1997
Minnesota Department of Natural Resources, Restore Your Shore CD-ROM, 2001
