Alfalfa

Alfalfa is a perennial legume that grows 30 to 90 cm tall, with trifoliate leaves, clusters of purple to violet flowers and coiled seed pods. Its taproot can reach several metres deep, which makes the crop remarkably drought-tolerant. Each pod holds a few tiny, kidney-shaped seeds that are yellow to olive-brown and about 2 mm long.

As a food, the seeds are sold for sprouting, and the finished sprouts are thin, pale white stems with small green leaf tips, crisp, juicy and mild with a faintly nutty, grassy flavour. Dried leaf is sold as powder and tea, and seed is also marketed in bulk for field sowing. Seeds are typically sold untreated for sprouting.

Alfalfa is native to southwestern and central Asia, with the region of Iran and the surrounding areas often given as the centre of origin, and it is among the oldest cultivated forage crops. It spread with horse-keeping peoples and later through Greek, Roman and Arab agriculture into Europe, North Africa and beyond.

The name alfalfa comes through Spanish from Arabic al-fasfasa, meaning the best kind of fodder, and the British name lucerne comes via French from the Provençal word for the plant. Its scientific species name sativa is Latin for cultivated.

Alfalfa has been grown for animal feed for several thousand years and was prized for horses; ancient Persians and later Greeks and Romans grew it for their cavalry and livestock. Arab farming brought it to Spain, from where Spanish colonists carried it to the Americas in the 16th century. In the 19th century, it reached California with Chilean seed during the Gold Rush and became one of the most important crops in the western United States.

As a nitrogen-fixing legume, alfalfa improves soil, and it is a key feed for dairy cattle and horses worldwide. The use of alfalfa seeds for human food began on a small scale in Asia but became notable in the 1970s when sprouts became staples in American health-food stores and sandwich shops.

Sprouts then drew attention for food-safety problems. Seeds can carry bacteria, and warm, humid sprouting conditions allow them to multiply, leading to Salmonella and E. coli outbreaks in several countries. Authorities responded with seed testing, disinfection guidelines and advice for vulnerable groups to avoid raw sprouts. Alfalfa remains a major forage crop, and the sprouts are a niche but familiar salad ingredient.

Sprouts are eaten raw in salads, sandwiches, wraps and sushi, or added to soups and stir-fries at the end of cooking. Dried alfalfa leaf is made into tea and powder supplements, and in some regions young leaves are cooked as a green. Seeds are occasionally ground into flour in trace amounts.

In agriculture, alfalfa is grown for hay, silage and grazing, as a cover crop and for honey production, as it is an important nectar source for bees. Home sprouters grow it in jars with daily rinsing, usually for four to six days, before refrigerating the finished sprouts.

Alfalfa sprouts are very low in calories and provide vitamin K, vitamin C, folate and small amounts of minerals and fibre. Claims that alfalfa lowers cholesterol or blood sugar mostly come from animal and small human studies and are not well established. Sprouts contribute freshness and nutrients to meals but are not a significant protein source in realistic portions.