Garden cress, also known as peppergrass, is a fast-growing, annual herb in the Brassicaceae family. It is a small-to-medium sized plant grown commercially in soil, hydroponically in water, and in containers for individual use. Its tangy, peppery flavor makes garden cress a favorite of chefs, especially in Europe. Throughout history, people have used this herb to treat many different health conditions. Care must be taken when consuming this herb because it has potential unpleasant side effects.
This herb is native to northern Africa. It can be grown in all U.S. Department of Agriculture Hardiness Zones because it is an annual and lasts for only one growing season. Garden cress prefers full sunlight for eight or more hours per day. These plants can be grown in soil or hydroponically in water with an acidic, mildly acidic, or neutral pH level. Cress seeds are typically planted in the early spring or fall.
Garden cress reaches maturity about 12 days after planting. In the wild, it can grow up to 2 feet tall (60 cm). Domesticated plants are between 6 and 12 inches (15-30 cm) tall. This relative of the mustard plant has tiny, clustered, white-to-pinkish blooms that are just 1/12th of an inch (2 mm) wide. The foliage is green and ruffled.
European and Indian chefs use garden cress as a garnish, in salads to add texture, or in sandwiches for added flavor and crunch. Its leaves are rich in iron, folic acid, calcium, vitamins C, A, and E, and folate. The seeds are high in both arachidonic and linoleic fatty acids and contain a considerable amount of protein.
Garden cress has been used in traditional medicine for new mothers to increase breast milk production, to regulate the menstrual cycle, help with iron uptake, and as an aphrodisiac. It has also been used to stimulate the appetite, as a laxative, and to settle colicky infants. The seeds act as an expectorant and have been used to treat asthma, sore throats, cough, and congestion. The phytochemical lepidimoide is found in its germinating seeds and has been shown to lower blood sugar following a meal. The arachidonic and linoleic acids are said to make garden cress a memory booster.
Experts familiar with the properties of this herb recommend eating it only in moderation because it can have significant side effects. This plant may induce an abortion or miscarriage if too much is consumed. Garden cress contains goitrogens which prevent iodine from being absorbed by the the thyroid gland. This can lead to hypothyroidism or exacerbate preexisting hypothyroidism. People who are sensitive to mustard oils may have digestive issues, including cramps and diarrhea, if they eat too much of this plant.