Grain Amaranth

Sowing: Grain amaranth is direct-sown once the soil has warmed, or raised in a nursery seedbed and transplanted into its permanent position two to three weeks later. Germination is quick and reliable in warm soil but poor in cool conditions, and a drop in nighttime temperature appears to encourage it.

Siting: It performs best in a warm, sheltered, sunny position with well-drained, fertile soil at a pH of 6 to 7, tolerating a range of 5.5 to 7.5. The crop grows most vigorously where daytime temperatures average 19–23°C and tolerates 10–32°C, but it is killed outright at 4°C or below; it prefers annual rainfall of 1,000–1,600 mm, tolerating anywhere from 500 to 2,500 mm.

Pests: Grain amaranth can be attacked by leaf-chewing insects and by aphids.

Toxicity: When grown on nitrogen-rich soil, particularly land treated with chemical fertilizers, the plant concentrates nitrates in its leaves, a buildup linked to health problems such as stomach cancers and blue-baby syndrome, making produce from synthetically fertilized plants inadvisable to eat.

Leaves: Leaves can be harvested within 30 to 50 days of sowing; if the plant is cut back rather than uprooted, it will keep producing leaves for a further 120 to 300 days.

Seed: As a seed crop it typically yields 800 to 1,200 kg per hectare, rising to as much as 3 tonnes per hectare where fertilizer is used.

Traditional use: For traditional medicinal preparations, the whole plant was harvested as it came into flower and dried for later use.

Culinary: Grain amaranth is grown for its edible leaves, cooked as a mild-flavored spinach substitute rich in vitamins and minerals, and for its seeds, which are eaten raw or cooked as a cereal substitute or popped like popcorn. The seed can also be soaked for about twelve hours and then sprouted for around eleven days before being added to salads; cooked whole, it turns gelatinous, and because the tiny grains are hard to fully crush, some pass through digestion undigested.

Ornamental: It is also grown as an ornamental, valued for its dense, catkin-like flower spikes in deep purplish-red or yellow-green that appear through summer and autumn.

Fodder: The seed has been studied as a feed ingredient for livestock, noted for a protein and oil content higher than conventional cereal grains such as corn or sorghum and considered useful for balancing animal diets.

Dye: Its foliage has yielded yellow and green dyes, and a red pigment extracted from the plant has been used to color foods and medicines.

Medicinal: Traditionally, the whole plant, astringent from its tannin content, was used internally for diarrhoea and excessive menstrual bleeding, gargled to soothe an inflamed throat and heal mouth ulcers, and applied externally to wounds, nosebleeds, and vaginal discharge.

Grain amaranth is thought to be endemic to Mexico and is considered near certainly the common ancestor of the genus Amaranthus, though how other species within it were domesticated remains unclear. Genetic and geographic evidence points to separate domestication events in Central America and South America, with Amaranthus hypochondriacus tied to Central America and elsewhere in North America, distinct from Amaranthus hybridus, believed to derive from South America.