At first they looked insignificant and harmless but these plants were really the devil in disguise. Like those really bad reptilian creatures with sharp teeth and claws who rampaged a town in the 1984 horror movie, Gremlins, I am currently under attack by a weed…. a devil weed, a dangerous villain, a Gremlin. It’s Garlic Mustard (Alliaria petiolata), a biennial plant in the Mustard family. Native to Europe, it is thought to have been brought to America in the 1860s as a culinary herb and indeed, it is edible.
The small rosettes of leaves appeared among my roses and lavender several years ago. I pulled up tons without recognizing the weed until successive years when the plant had matured into tall shoots, competing with the lavender, then moving on to other borders . Each year, I weed and weed and I think I’ve gotten it under control but when I turn my back, it multiplies as fast as those little Gremlins that terrorized an entire community.
It is a destructive invasive plant that is controlled best by hand-pulling before the plant goes to seed. Each mature plant can produce over a thousand seeds and once it produces seeds, it can become so prolific that it is difficult to eradicate. When it’s introduced into a new environment, it can aggressively spread into woodlands where it out-competes native plants and flowers that insects depend upon for life. The West Virginia White Butterfly (Pieris virginiensis) and the Mustard White Butterfly (Pieris oleracea) that lay eggs on Toothwort plants are choosing to lay eggs on Garlic Mustard which has proved toxic to both the eggs and larvae. The plant also produces toxins that suppress the mycorrhizal fungi that plants require for growth.
The plant has no natural enemies. For very heavy infestations where risks to desirable plants is at a minimum, applications of systemic herbicide glyphosate can be effective. Since the seeds remain viable for five years in the soil, diligent monitoring is important. After weeding, do not compost this weed as the plant can germinate in the compost bed.
Wish me luck.
PS: I uploaded the wrong photo. I moved and now I live in New Hampshire. Wikipedia supplied the photo of Garlic Mustard for this post.
Ann Hohenberger, The Garden Club of Gloucester