Turmeric

Turmeric grows as an upright perennial herb from thick, branching rhizomes, reaching about 40 inches tall. It does best in hot, humid conditions with full sun in the morning and afternoon shade, in rich, slightly acidic to neutral soil kept moist to occasionally wet; it suits USDA zones 8-11, and where winters are too cold it can be grown as an annual.

Propagation: New plants are grown by dividing the rhizomes, best done in spring or summer. Grown in containers, turmeric needs ample water and may require repotting, as its thick, branching rhizomes can grow large enough to split the pot.

Turmeric has no serious insect or disease problems. Red spider mites can appear on older plants, particularly when the soil is allowed to dry out, while young leaves may be damaged by slugs and snails.

Turmeric rhizomes are dug in fall once the foliage begins to wilt and dry out. Rhizomes intended for the spice are then boiled, dried, peeled, and ground, while rhizomes kept for replanting are stored in a cool, dry location until the next growing season.

Culinary: Turmeric's dried, ground rhizomes are the main ingredient in curry powder and are used to flavor and color many Asian cuisines, giving a warm, bitter, black pepper-like taste and an earthy, mustard-like aroma; fresh rhizomes can also be used directly without boiling and drying.

Dye and cosmetic: The bright yellow-orange dye in the rhizomes is also used as a food coloring and in fabrics and paints, and in India turmeric is applied cosmetically as well.

Traditional medicine: In India, Pakistan, and Bangladesh, turmeric rhizomes have traditionally been combined with other plants to treat headaches, wounds, snake bites, stings, sprains, and fractures, and the plant has long featured in Ayurvedic, Siddha, Unani, and traditional Chinese medicine.

Ornamental: Its large, clumped leaves and yellow-white flower spikes also make turmeric a plant grown in herb gardens and containers as a foliage and flowering ornamental.

Turmeric is thought to have originated in southwestern India, where it has been cultivated for more than 2000 years, and India remains its largest producer, consumer, and exporter. It is believed to be a hybrid between wild turmeric and other related Curcuma species, with cultivation later spreading to Bangladesh, China, Thailand, Cambodia, Malaysia, Indonesia, and the Philippines. Long domestication has left the plant unable to set fruit, so it can now only be propagated vegetatively by dividing its rhizomes.