Mustard is grown for its seeds and leaves. The seeds are the ingredient in the common prepared mustard condiment. Mustard is easy to grow from seed at home, even in cooler climates, and often grows as a volunteer plant in gardens. Mustard seeds can be found in garden stores or gathered from mustard plants.
Mustard seed should be sown one-fourth inch deep and three inches apart, but later thinned to be five to nine inches apart. Rows should be spaced a foot apart. Sowing should take place in the early spring and the early fall. If you are tilling your garden prior to sowing, only till shallowly so that water will remain in the top layer of the soil and the seedlings will come up evenly. You can start the mustard seeds indoors if desired.
Mustard seeds like growing in cool weather. However, if they are grown in hot weather, the leaves will become tough and spicy, which is a treat in certain culinary dishes. Mustard plants like getting lots of sun and water, so plant them in a clear, sunny area and water them during dry periods. A weeded garden bed will minimize the mustard's competition for water with other plants.
Stages of Growth
Mustard seeds will sprout quickly, within three to 10 days. They will grow rapidly at first, creating tender leaves that can be eaten in salads. Then, the leaves will grow large, tough and spicy. These leaves can be used in braised salads or with other strongly flavored foods. Next, the plants will bolt, creating yellow flowers that will eventually pollinate and develop seeds. These seeds can be used for making prepared mustard or mustard powder. Mustard plants, at full maturity, can reach 30 to 45 inches tall.
Mustard plants face problems from insects and illness. Aphids, flea beetles and cabbage moths can infest a mustard crop, but they can be treated with organic pesticides. Downy mildew, white rust, sclerotinia stalk rot, leaf spot and virus mosaic are among the diseases to which mustard is susceptible. One treatment is to be sure that plants are spaced far enough apart to allow for air circulation. Another is to avoid watering the plants in the evening.
In the Wild
Wild mustard, or Synapis arvensis, comes from Eurasia but has grown in the United States since the 1700s, where it is now widespread. It grows easily in disturbed areas and is highly adaptable. Like cultivated mustard, it is edible and has a spicy flavor, but it has much smaller leaves than cultivated mustard. Cultivated mustard seeds can go wild, escaping the garden and growing in lawns or along roads.