How to grow red amaranth
Overview
Red amaranth (Amaranthus cruentus) is a fast-growing leafy vegetable grown for its tender red-tinged leaves and young tips. It thrives in heat and is best treated as a warm-season crop that will bolt if exposed to cold.
Varieties
- Red Garnet — Deep red leaves, very tender, popular in Australian gardens.
- Green Callaloo — Green leaves with red veins, good for Caribbean-style cooking.
Soil Preparation
Prefers a pH of 6.0–7.0 in rich, well-drained soil. Amend with compost or well-rotted manure before planting to boost fertility. Avoid heavy clay; if present, add gypsum or grow in raised beds.
Growing Guide
Sow seeds 5mm deep in well-drained, fertile soil in full sun. Space plants 20–30cm apart for regular leaf harvest, or 40cm for larger plants. Keep soil consistently moist but not waterlogged; mulch to retain moisture. Succession sow every 3 weeks for a continuous supply. In cooler zones, wait until soil is above 15°C before planting.
Sowing
Sow seeds 5mm deep, 10–15cm apart, and thin to 20–30cm. Germinates in 5–10 days at 20–25°C. Direct sow is best; transplant only if using cell trays to avoid root disturbance.
Care
Feed every 2–3 weeks with a balanced liquid fertiliser (e.g., 10-10-10) to sustain rapid leaf growth. Pinch out tips regularly to encourage bushiness and delay flowering. Remove any lower leaves that yellow or touch the soil to prevent disease.
Companion Planting
Plant with corn, beans, and cucurbits to share warmth and shade. Avoid planting near potatoes or onions, as they may compete for nutrients. Good as a living mulch under taller crops.
Common Pests & Risks
Aphids and flea beetles are common; control with a strong water spray or neem oil. Caterpillars (e.g., cabbage white) can be hand-picked or treated with Bacillus thuringiensis. Avoid overhead watering to reduce fungal issues.
Harvesting
Harvest young leaves and tips from 6 weeks after sowing, when plants are 20–30cm tall. Pick regularly to encourage bushiness and delay flowering. For a continuous supply, cut the whole plant at 40cm and let it regrow from the base.
In the Kitchen
Use young leaves raw in salads or cooked like spinach. Tips can be steamed or stir-fried. Store in a plastic bag in the fridge for up to 5 days. The red colour adds visual appeal to dishes.
Troubleshooting
Yellow leaves: overwatering or poor drainage; reduce water and improve soil. Stunted growth: cold soil or frost; wait for warmth or use cloches. Bolting early: heat stress or long days; harvest more often to delay. Leaf spots: fungal from overhead watering; switch to drip irrigation. Leggy plants: too much shade; move to full sun.