Garlic mustard is an invasive species native to Europe, but its superabundance makes it ideal as the main ingredient in pesto, which requires large quantities of greens.
In addition, this tasty plant is nutritious and versatile, with roots that can be used to make horseradish and seeds that serve as a spicy condiment. Like all wild plants, it contains vitality above and beyond that of cultivated plants, and it doesn’t cost anything to harvest. In fact, many gardeners yank it out and throw it away.
Garlic mustard (Alliaria petiolata) tends to grow in places of partial shade. It likes the edges of things such as woods, lawns, fences, foundations, and it grows in open woods. The plant is easy to identify. Although the foliage visually resembles other plants with roundish, heart-shaped leaves, such as violet and ground ivy, three features make it distinctive. The edges of the leaves are scalloped, and the veins form a mosaic pattern. The clincher is the smell of the crushed leaf, which is similar to that of garlic. The plant is in the mustard family, but it imitates the smell and taste of the Allium species, such as onion and garlic, which are avoided by most insects. (There are no poisonous plants that smell or taste like garlic.)
The garlic mustard plant is a biennial, with a two-year life cycle. When the seeds sprout, usually in late summer or fall, heart-shaped basal leaves grow straight from the ground. The leaves stay green all winter and may be harvested even when there is snow on the ground, if the attentive forager knows where to find them. In early spring of the second year, the plant puts up a knee-high flower stalk with stem leaves that are roughly triangular in shape but still have the scalloped edges, mosaic vein pattern, and garlicky smell. The small white flowers are four-petalled, like all plants in the mustard family, and occur in clusters.
The leaves and flowers add a pleasant, pungent tang to salads or soups and make an excellent substitute for basil in a pesto recipe. Sometimes the result has a bit of a mustardy bite, but a couple of days in the refrigerator will sweeten up the flavor. The vitality of a wild pesto is several notches above that of a store-bought product.
By midsummer, most of the plants go to seed. The tiny, oblong black seeds are contained in long, narrow tan pods that stick out from the stem at 45-degree angles. The seeds may be harvested by shaking the pods over a paper bag. They are spicy and can be sprinkled on food as a condiment, or a prepared mustard can be manufactured from the ground seeds and vinegar. The roots of the first-year plants, harvested in spring or fall, make a horseradish when put into a blender with vinegar.
Like other members of the mustard family (broccoli, kale, cauliflower), garlic mustard is high in vitamins B and A, calcium, potassium, and cancer-preventing antioxidants.
