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How to Grow Amaranth

Amaranthus

Tender Warm Season Continuous Harvest

When to Start

Start seeds indoors 4 weeks before your last frost date. Transplant outdoors once night temperatures stay above 10°C and soil has warmed to at least 18°C.

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Growth Stages

Sow seeds
Germination ~8d
Harvest ~55d

Approximate days from start

Care Essentials

  • Balanced feed at planting. Drought-tolerant once established.
  • Dual-purpose — edible leaves and grain. Dramatic ornamental plants. Love's-lies-bleeding is the most popular ornamental type.

Companion Planting

Growing Conditions

Min. soil temperature: 18°C+
Germination temperature: 20–30°C

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Spacing & Planting

Plant spacing 30 cm
Row spacing 45 cm
Sow depth 0 cm
Mature height 120 cm
Mature spread 45 cm

Amaranth can be grown for both leaves and grain. For mixed use and medium to tall varieties, 30 cm between plants and 45 cm between rows gives good airflow and support while still achieving a full canopy. Leaf-only crops or smaller varieties can be planted a little closer, while very tall grain types can be spaced up to 60 cm in-row and between rows.

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Care Guide

Feeding
Balanced feed at planting. Drought-tolerant once established.
Watch for
  • Aphids
  • Flea beetle
  • Slugs on seedlings

Pests & Diseases

Pest Flea Beetle

Identification: Tiny round holes shot through leaves, small shiny beetles that jump when disturbed

Organic treatment:
  • Cover seedlings with fine mesh or fleece from sowing
  • Water regularly to keep plants growing strongly through damage
  • Sticky traps placed near plants
Chemical treatment:
  • Pyrethrin-based sprays as a last resort
Pest Aphids

Identification: Clusters of small green or black insects on shoot tips and undersides of young leaves, sticky honeydew

Organic treatment:
  • Strong jet of water to dislodge
  • Encourage ladybirds and hoverflies
  • Insecticidal soap spray
Chemical treatment:
  • Fatty acid sprays
Pest Slugs and Snails

Identification: Irregular holes in leaves, slime trails visible on soil and foliage, worst damage overnight

Organic treatment:
  • Beer traps sunk into the soil
  • Copper tape around pots
  • Evening hand-picking
  • Nematode biological control (Phasmarhabditis hermaphrodita)
Chemical treatment:
  • Ferric phosphate slug pellets
Disease Damping Off Pythium spp. / Rhizoctonia solani

Symptoms: Seedlings collapse at soil level, stems become thin and water-soaked, patches of seedlings fail

Treatment: Remove affected seedlings immediately, improve ventilation

Prevention: Use clean compost, avoid overwatering, sow thinly, ensure good air circulation

Disease Stem Rot

Symptoms: Dark, water-soaked lesions at the base of stems, wilting and collapse of mature plants

Treatment: Remove and destroy affected plants, avoid replanting in the same spot

Prevention: Ensure good drainage, avoid overwatering, space plants for airflow

Growing Conditions

Min. soil temperature18°C
Germination temperature20–30°C
Base growth temperature10°C
Min. daylength to start11h
Photoperiod sensitivityday neutral

Frequently Asked Questions

How far apart should I plant Amaranth?
Plant Amaranth 30cm apart with 45cm between rows.
When can I harvest Amaranth?
Amaranth is ready to harvest approximately 35 days after transplanting.
Is Amaranth frost hardy?
Amaranth is classified as Tender.

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