Guide to Growing Amaranth
Amaranth was grown as a food crop in Latin America for thousands of years before the arrival of the Europeans. It declined significantly in popularity in the Americas after that, though at the same time it spread to other areas of the world, including Africa and India, and established itself to a modest degree there. In recent decades it has experienced a bit of a resurgence, regaining some of its past popularity in the Americas, and becoming more commonly grown in countries such as Russia and China. In the United States, it is most often found in health food stores and organic markets.
There are many varieties of amaranth, so you'll want to make sure you're planting the one most appropriate for the use you intend. In addition to the varieties whose seeds are used as a grain, there are some that are valued primarily for their spinach-like edible leaves and others that are grown not as food crops at all but for the beauty of their flowers, one popular example being the love-lies-bleeding variety. Amaranth flowers can be many colors, including pink, purple and red.
Planting
Amaranth is able to grow in a wide range of soils, but it does best in a rich, well-drained loam. It should be planted after the last frost in spring, or started indoors about three weeks or more prior to that and then transplanted. It prefers full sun.
Plant the seeds about a half inch deep, in clumps or rows at least a foot apart. A nitrogen-rich fertilizer can maximize your yield. Frequent watering is not necessary, as amaranth is moderately drought and heat resistant. It is not a difficult plant to maintain.
Pests and Diseases
Many insects will chew on amaranth, but only heavy infestations will do significant harm, so there's no reason to overuse pesticides because of light leaf damage.
Amaranth does not appear to be prone to any viral or bacterial diseases, though it can be vulnerable to fungus in wet soils.
Amaranth develops slowly in its early stages and can be dominated by weeds, so stay on top of the necessary weeding until the plants are at least six inches tall and can outcompete the weeds.
Harvesting
The leaves from the amaranth plant can be harvested at any time. The earlier they are taken, the more tender they will be. Older leaves will have a stronger flavor. The young stems are edible as well.
For the seeds, allow the plant to fully flower, and wait until you see some of the flowers start to brown and die. Some gardeners wait until frost kills the plants. Cut off the flowers and store until fully dry. Thresh over a cloth or inside a bag to release the seeds. Use wind or water to separate the grains from the chaff.
Enjoying
Use amaranth leaves in salads or anywhere you would use spinach.
Amaranth as a grain is used similarly to cereal grains such as wheat and oats. The seeds can be popped, flaked, or ground into a flour to use for bread, crackers, cookies, breakfast cereal and other foods. A popular use in Mexico is to mix amaranth with honey or molasses to make a sweet snack bar or snack cake.
Amaranth is a highly nutritious food, rich in protein and high in fiber.
Amaranth is also used in the production of natural, non-toxic red dyes.
Sources:
"Growing Amaranth as a Food Plant." Tropical Permaculture.
"How to Grow Amaranth." Heirloom Organics.
"Tips for Growing Amaranth for Food." Gardening Know How.