Amaranth

Amaranth (Amaranthus cruentus) gives you two harvests from one planting: young leaves as a spinach substitute that holds up in summer heat, and mature seed heads that yield a grain at $4-7/lb (USDA AMS Specialty Crop Market News, 2023). Most warm-climate gardeners are growing it already without realizing it - common pigweed (A. retroflexus) is an amaranth, and it grows in the same conditions for the same reasons the cultivated forms do.

What you’re actually growing

The genus Amaranthus contains over 60 species, several of which are grown for food. The main cultivated food species are A. cruentus (red or purple grain types, Central American origin), A. hypochondriacus (Mexican grain types), and A. tricolor (primarily grown for greens in Asian cuisine). In practice, seed packets labeled “grain amaranth” are usually A. cruentus or A. hypochondriacus; “vegetable amaranth” or “Chinese spinach” refers to A. tricolor.

Grain amaranths grow 4-8 feet tall with large, showy seed heads - burgundy, gold, or orange depending on variety. The seed is tiny, roughly 1.5mm in diameter, technically a pseudocereal (like quinoa) - not a grass, but functionally used as one. Amaranth grain is gluten-free and contains lysine, an amino acid low in most cereal grains.

For greens: harvest young leaves from any amaranth before the seed stalk bolts. Flavor is mild, like spinach, with a slightly earthy note. Nutritionally similar to spinach in terms of iron and vitamin A content.

The ROI case

A $2.49 seed packet germinates densely. Thin to 12-18 inches apart for grain production; 6 inches apart for greens-only harvest where you want smaller, more tender plants. Direct sow after last frost - amaranth does not transplant well past early seedling stage.

For greens: begin harvesting outer leaves at 4-5 inches of plant height, from about 30 days after germination. Continuous harvest of outer leaves slows bolting. At 0.25-0.5 lb per plant of greens, and $4-6/lb (USDA AMS, 2023), one packet’s worth of plants spread over 20 feet returns $8-20 in greens value from repeated harvests.

For grain: let plants run to mature seed heads. A single grain amaranth plant produces 40,000-60,000 seeds weighing 1-3 oz of grain (University of Kentucky Cooperative Extension, Grain Amaranth Production, 2019). At 6 plants per row foot and a 10-foot row, that’s 60 plants potentially yielding 3-12 lb of grain. At $4-7/lb, the gross value from a 10-foot row is $12-84 depending on variety and conditions.

Growing requirements

Amaranth tolerates poor soil, heat, and drought better than any common annual vegetable. This is not a minor benefit - it is the primary reason to grow amaranth. In July and August when lettuce bolts, spinach is finished, and most greens are unusable, amaranth is at peak production.

Soil pH 6.0-7.5. Amaranth fixes no nitrogen but grows adequately in low-fertility soil. Modest phosphorus at planting improves seed set in grain types. Avoid heavy nitrogen fertilization - it drives rapid lush growth that can cause lodging (stem collapse) in tall grain varieties.

Direct sow seeds 0.25 inches deep after soil temperature reaches 60°F. Seeds are tiny - mix with sand for even distribution if broadcasting. Thin aggressively: amaranth self-thins poorly and crowded plants produce spindly stems that lodge before harvest.

No supplemental water needed once plants reach 12 inches tall in most climates. Young seedlings need consistent moisture during the first 2-3 weeks. Drought stress during active growth reduces greens yield; grain fill is more tolerant.

What goes wrong

Tarnished plant bug (Lygus lineolaris) pierces developing seed heads and injects a toxin that kills seed tissue, leaving blank spots in the mature seed head. Row cover at seed head formation in high-pressure areas reduces impact. No reliable spray treatment for organic production.

Aphids cluster on seed stalks in dense colonies late in the season. Natural predators usually arrive before the damage is serious. Insecticidal soap for severe infestations.

Damping-off (Pythium and Rhizoctonia spp.) kills seedlings before they reach 2 inches. Amaranth seedlings are vulnerable. Sow in well-drained soil, avoid overwatering at germination, and do not cover seeds more than 0.25 inches deep.

Stem boring insects can enter at the base of tall grain plants after seed head formation, causing lodging. Cut affected stems and dispose of them. Rotate amaranth out of infested beds.

Amaranth that self-seeds can become a persistent weed in managed beds - not unlike its wild relatives. Deadhead or harvest seed heads before any seed shatters if you need to control spread.

Harvest and storage

For greens: harvest outer leaves continuously. Young leaves are most tender; mature leaves are still edible but tougher. Stop harvesting greens 3-4 weeks before you want the plant to develop a mature seed head - the plant needs its leaf area to fill grain.

For grain: the seed head is ready to harvest when you can rub it between your palms and seeds fall freely. At this stage most of the head has turned from colorful to tan or brown. Cut entire heads and hang upside down over a sheet or barrel for 1-2 weeks in a dry location.

Thresh by rubbing the dried heads over hardware cloth (0.5-inch mesh) to separate seeds. Winnow by pouring slowly in front of a fan to blow away chaff. Grain amaranth must be rinsed before cooking to remove saponins (bitter compounds) - place in a fine-mesh strainer and run under cold water for 30 seconds before cooking.

Store cleaned, dry grain in airtight containers for 1-2 years.

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Related crops: Corn, Arugula

Related reading: Beginner Homestead Crops - crops that perform reliably in difficult conditions