Garlic Mustard

Garlic Mustard Impact – A noxious biennial herb averaging 3 + feet that emerges in early spring. Native to Europe, Asia & NW Africa, it invades moist forests, wooded streambanks, roadsides and trail edges where it disrupts normal plant – fungi relationships that results in elimination of native species. Its roots exude compounds that alter soil chemistry to favor its survival at the expense of other species. Each plant can produce thousands of seeds. Difficult to control once established.

How to identify – It begins as an inconspicuous first year plant (rosette) that look similar to wild violets having triangular somewhat heart shaped leaves that have coarsely toothed margins and wrinkled leaf surfaces. 2nd year -it can send up multiple stems with a tall flower spike with four petal white flowers developing into slender pods bursting with tiny round seeds. 2nd year leaves have sharp teeth. Leaves & single stems produce distinctive garlic odor when crushed. Seeds may be viable for 10 years.

Control – Garlic mustard is not browsed by herbivores and has no effective insect pests or diseases. Small infestations can be hand pulled before seed production by late June. All root material must be removed and bagged and solarize (left in sun for at least two weeks before disposal). Pulling up large swaths of garlic mustard is futile. Large infestations- use a foliar herbicide spray such as Glyphosate or Triclopyr. Do not compost! Monitor site in fall and pull any new plants. It may be edible, unfortunately eating it has not worked well as a control strategy.

There have been studies that suggest that not managing it / i.e., leaving it alone for 10 years, it becomes scarce as a species and the remaining plants greatly stunted. Where it has been “managed”, the plants are considerably larger and cover a higher percentage of a site.

Best strategy, don’t let it get established.