Have you heard the phrase "if you can't beat them, eat them"? Landowners may draw this conclusion for some invasive species which are edible, like garlic mustard (Alliaria petiolata). First introduced to the U.S. in the late 1800s, garlic mustard is a European herb that spread rapidly into the wild and is now one of the worst invaders of the forest understory in the Northeast.
A quick search on the Internet yields recipes and commentary about how the use of garlic mustard in pesto is an added reward to controlling infestations. A colleague prepared garlic mustard pesto pasta for a potluck meeting, but I have yet to make it myself. If you are unlucky enough to have a garlic mustard infestation on your property, and daring enough to try this invasive culinary innovation, remember a few important guidelines: always confirm the identification of the plant before consuming; ensure that the area where it is growing is free from chemical substances; and, thoroughly wash plants.
Harvest garlic mustard by taking out the entire plant including the roots early in the season before it has a chance to flower. Young first leaves, I am told, are best for pesto (and for salads or as a steamed green). Use only the leaves for this recipe. Mix with olive oil, pine nuts and parmesan cheese. Add basil and garlic, too, if desired.
Garlic mustard plants
Garlic mustard flowers
Garlic mustard infestation
Garlic mustard seed pods
(Photos courtesy of www.bugwood.org)
Regardless of whether you intend to eat your way through an infestation or not, when pulling plants, bag and remove the roots from the area you are clearing because they will re-establish themselves if left in a pile on the ground. If you pull up garlic mustard after it has flowered, beware, because it will develop the seedhead even after it is pulled. And remember, despite its temporary use in cooking, garlic mustard causes long-lasting irreparable damage to natural areas. Maintaining cultivated populations is not recommended.
Like most invasive plants, garlic mustard forms expansive monocultures and crowds out beneficial natives, which deprives wildlife of essential food sources. It outcompetes native herbaceous plants by reducing light, moisture and space. Garlic mustard has negative impacts below ground, too. It disrupts beneficial fungi associated with the roots of northern hardwood trees, allowing it to compete with tree species.
Now is the time to identify garlic mustard, although it is in various stages of growth across the region. In lower elevations, plants 2 to 3 feet in height are already visible with buds or flowers. In higher elevations, the plant may still be short in stature. Since it is a biennial plant, it has two forms. The first year garlic mustard appears as small kidney-shaped leaves growing in rosettes close to the ground. In its second year, it grows to 3 feet and has sharply toothed, heart-shaped leaves arranged alternately along the stem. In May and June, small, white, 4-petalled flowers will form at the top of the second year, plants, later developing slender, greenbean-shaped seedpods. Seed production is one of this invasive plant's strongest assets: garlic mustard releases thousands of seeds that can persist for more than five years!
Efforts to document locations of garlic mustard and remove infestations are under way. Disturbed areas are most susceptible to rapid invasion and dominance, especially where native vegetation has been removed. Inventories of roadsides, campgrounds, and trails reveal that these are likely locations to find this invader. You can help by reporting sightings of garlic mustard or other forest invaders to the Adirondack Park Invasive Plant Program at (518)?576-2082. Learn more about invasive species prevention, detection and management in the region online at www.adkinvasives.com.
Eye on Invasives is a biweekly column that spotlights a top invader when it is easiest to identify. Hilary Smith directs the Adirondack Park Invasive Plant Program, a partnership program housed at the Adirondack Chapter of The Nature Conservancy in Keene Valley, NY. Find out more about this award-winning program online at