Garlic Mustard: A Palatable Pest

At Brooklyn Botanic Garden, it's usually our policy to discourage people from harvesting wild plants for their garden or kitchen. Irresponsible collecting or foraging can degrade wild plant communities, so we generally recommend the use of nursery-propagated or farm-grown material instead.

However, in the case of certain plants—namely invasive exotic weeds—we do make an exception. Indeed, we actively encourage you to get out there and harvest with a vengeance. You won't just be doing the environment a favor; some of these exotics are actually edible, taste great, and can add an interesting dimension to your meals.

One species we'd like to see culled to oblivion is garlic mustard (Alliaria petiolata). Native to Europe, this cool-season biennial is wreaking havoc on deciduous forests from New England west to Wisconsin and south to Tennessee. First introduced here as a winter potherb in colonial times, it is gradually displacing many native woodland wildflower populations. The damage isn't confined to disturbed habitat, as it is with many other invasives; this plant spreads readily through healthy forestland as well.

Garlic mustard is not an unattractive plant. In the first year of its life cycle, it develops a ground-hugging rosette of toothed, kidney-shaped leaves that persist through the winter in most regions. In its second year, the plant sends up one or two flower stalks, this time with toothed, triangular leaves. Growing from one to four feet high, these stalks produce numerous white blossoms in May that eventually develop into elongated seedpods.

A number of factors contribute to garlic mustard's success as a weed. Since there's no winter dieback, the plant gets a head start over the competition. It thrives in partial shade and moist soil but seems to tolerate sunny conditions as well. It's also a prolific seeder. And it has no natural enemies (though we hope that'll change once you've read this article).

Garlic mustard is not difficult to find or identify. As well as being a scourge in woodland areas, it's a common roadside and garden weed. The winter rosette of green makes it easy to spot, and its spring flowers have four distinct slender petals each, a characteristic of members of the Brassicaceae or mustard family. Probably the most distinguishing feature, however, is the scent the leaves give off when crushed. It is, as you've probably figured out already, somewhat akin to garlic, with a little onion thrown in for good measure.

It's no mystery why settlers thought to bring this particular herb with them to the New World—it was something fresh to flavor their soups and stews with during the cold, drab winter months. Both the roots and leaves of the plant are edible.

But the culinary potential for garlic mustard shouldn't be limited to its Old World uses. Think delicious winter invasive-plant salads, mouth-watering invasive-plant omelets, or perfectly cooked pastas infused with invasive-plant pesto (see "Garlic Mustard Pesto," below, for more details).

The New York Invasive Plants Council, a coalition of public and private organizations dedicated to controlling invasive species, lists garlic mustard among the top 20 problem weeds in the state. The group recently started its own campaign to get more mouths munching on the plant.

If you take a look down the top-20 list, published on the council's web site, you'll also find Japanese knotweed (Polygonum cuspidatum), which causes major problems in native wetland ecosystems. But guess what? This plant's edible too. Its early-spring shoots taste like rhubarb and can be used in a similar fashion.

Knotweed shoots are even tastier than rhubarb, according to Steve "Wildman" Brill, author of The Wild Vegetarian Cookbook, who has concocted such tantalizing confections as apple-and-knotweed pie, knotweed sherbet, and strawberry-knotweed cobbler.

There you have it, folks: invasive-plant dinner and dessert. Bon appétit!

Garlic Mustard Pesto

• 4 cloves garlic, peeled
• 3 tablespoons garlic mustard taproots
• 3/4 cups parsley
• 1 cup garlic mustard leaves
• 1 cup basil
• 1 1/2 cups low-sodium olives, pitted
• 2 cups walnuts
• 1 cup pine nuts
• 1/2 cup mellow miso
• 1 1/4 cups olive oil or as needed

Chop the garlic and garlic mustard roots in a food processor. Add the parsley, garlic mustard leaves, and basil and chop. Add the nuts and chop coarsely. Add the olive oil and miso and process until you've created a coarse paste. Makes 4 cups.