Amaranth, a staple crop of the Aztecs and Incas, is an annual plant known for its versatility. It allows cultivators to harvest tender, nutritious greens early in the season while still yielding protein-rich grain later on. Amaranth thrives in warm conditions, making it an excellent, high-yield, dual-purpose crop for gardeners.
Preparing the Growing Environment
Successful amaranth cultivation begins with selecting a site that receives full sun exposure, ideally six or more hours of direct sunlight daily. The plant is highly tolerant of heat but requires well-drained soil to prevent root issues. Amaranth prefers a soil pH that is slightly acidic to neutral, typically ranging from 6.0 to 7.5.
Planting should only occur after the danger of the last spring frost has passed, as this crop is sensitive to cold temperatures. The soil temperature is a more accurate indicator than the air temperature, with a minimum of 50°F necessary for germination, though 68°F or warmer is better. Before planting, incorporate organic matter like finished compost into the soil to improve structure and provide initial nutrients.
Planting and Thinning Techniques
While amaranth can be started indoors four to six weeks before the last frost, direct sowing into the garden soil is often the preferred method. The seedlings of this plant can be sensitive to root disturbance, meaning that transplanting them may cause a temporary setback in growth. Seeds should be sown very shallowly, barely covering them with soil or placing them no deeper than a quarter-inch.
Once seedlings emerge, thinning is necessary to prevent overcrowding and stunted growth. If the primary goal is to harvest greens, thin the plants to stand approximately three to four inches apart, which encourages maximum leaf production. If the intention is to harvest the grain, the plants must be spaced much wider, typically 10 to 18 inches apart, to allow for the development of large, robust seed heads.
Ongoing Care and Pest Management
Amaranth is generally a low-maintenance plant once it has become established in the garden. Although it exhibits good drought tolerance, particularly after the initial growth phase, consistent moisture is beneficial for achieving the highest yields. Aim to provide about one inch of water per week, ensuring the soil remains moist without becoming waterlogged, which could lead to root rot. Supplemental fertilization is usually unnecessary, as too much nitrogen can promote excessive leafy growth at the expense of grain production.
The plants are susceptible to a few common garden pests, including aphids and flea beetles. Aphids can be managed effectively by spraying the infested areas with a gentle stream of water or an insecticidal soap solution. Flea beetles can be deterred by covering young plants with a lightweight floating row cover immediately after planting. Organic options like neem oil or wood ash can also be applied to address various pests.
Harvesting Amaranth (Greens and Grain)
The dual-purpose nature of amaranth allows for two distinct harvests from the same plant, starting with the greens. Young, tender leaves can be harvested as early as 25 to 40 days after planting. Utilizing the “cut-and-come-again” method, you can continually harvest the outer leaves or cut the top half of the plant, which encourages the development of new side shoots and a prolonged yield of foliage.
To harvest the grain, allow the plant to mature fully, typically 100 to 120 days after planting, when the large seed heads begin to dry and turn brown. The seeds are ready when they readily fall from the flower head with a gentle rub of the fingers. Cut the entire seed head and place it in a paper bag or on a tarp to finish drying in a cool, sheltered location. After drying, the seeds are separated from the chaff by threshing (rubbing or beating the heads) and winnowing (using a light breeze to remove debris).