How to Grow Blood Amaranth

Quick Facts

Factor	Value
Soil pH	6.5 - 7.5
Optimal growing temp	22-28°C
Minimum growing temp	10°C
Soil texture	Chalk, loam, sand; grain-production soils medium-to-high in P and K
Drainage	Moist but well-drained
Lifecycle	Annual.
Edible parts	seeds, leaves
Documented problems	4 diseases, 2 pests

At a Glance

Diseases

Damping-off (seedling collapse)

moderate

Rhizoctonia solani

Damping-off (seedling collapse at soil line); Wilting with chlorotic, dropping leaves

Documented for amaranth broadly (Ghana peri-urban survey; UF/IFAS).

Wet rot / stem rot

high

Choanephora cucurbitarum

Water-soaked wet rot with white silky mycelium

Main fungal disease of concern per UF/IFAS; among most prevalent in Ghana survey.

Anthracnose

moderate

Colletotrichum spp.

Sunken reddish-brown lesions with yellow halo (anthracnose)

Observed in 91% of surveyed farms in Ghana study.

Amaranthus virus diseases (unspecified/unidentified)

unknown

RHS: "may be susceptible to a virus" -- no specific virus identified.

Pests

Amaranth stem weevil and leaf-feeding caterpillars

moderate

Hypolixus truncatulus; Spodoptera spp.; Hymenia recurvalis

Grain amaranth species named explicitly by UF/IFAS as hosting stem weevil and leaf caterpillars.

Aphids

unknown

Aphididae (various spp.)

RHS: "may be susceptible to aphids".

Soil & Growing Conditions

Water: Full sun, sheltered site. Moderately fertile, humus-rich, moist soil; water freely in summer to prolong flowering. Drought resistant (RHS). For grain production specifically, optimal soil pH 6.5-7.5 (Univ. of Wisconsin Extension); RHS notes broader ornamental-garden tolerance of acid-to-alkaline soils.

Soil pH range

6.5 7.5

Span reflects genuine variation between the cited authorities, not a single agreed figure.

Growth Stages

1. Establishment: Propagate by seed (RHS); for grain production, seed diluted with carrier and drilled at ~5 lb/acre (Univ. Wisconsin Extension).
2. Vegetative Growth: Upright annual to 2m tall, purple-flushed dark green ovate leaves (RHS).
3. Flowering: Clusters of tiny reddish-pink flowers in upright to arching spikes, summer into autumn (RHS).
4. Fruit Development: Grain-type seed heads develop after flowering.
5. Ripening / Harvest: Grain harvested once seed heads dry and thresh freely (general grain-amaranth practice; needs species-specific day-count verification).
6. Senescence / Dormancy

Harvest & Storage

When to pick: Two harvests come off one plant, and they are read differently. Leaves: the first picking is ready roughly 30-50 days after sowing, and the plant will keep giving cuttings for many months afterwards (Ecocrop, via Useful Temperate Plants). Grain: the seed head is left standing until it dries down and the seed threshes free when a head is rubbed between the fingers. In a cool summer the crop rarely dries fully on its own -- the Alternative Field Crops Manual (Purdue NewCROP) states that "a killing frost must occur before harvest followed by a week of good drying weather", and Iowa State Extension likewise has growers wait until about a week after the first hard frost. Cut before the heads begin to shatter or the plants lodge, since seed lost that way cannot be recovered.

Sources

1. African Journal of Agricultural Research (peer-reviewed; Appiah-Kubi et al. 2022, DOI 10.5897/AJAR2022.15985) - Survey of fungal diseases associated with amaranth (Amaranthus species) in peri-urban vegetable farms in Kumasi and Tamale metropolis of Ghana

   Field survey of 43 peri-urban Amaranthus farms; identifies anthracnose (Colletotrichum), wet rot (Choanephora cucurbitarum), wilting/damping-off (Fusarium, associated genera), and stem canker (Phoma/Alternaria) as the major fungal diseases.

2. FAO EcoCrop - Amaranthus cruentus data sheet
3. GBIF - GBIF Backbone Taxonomy match: Amaranthus cruentus
4. Useful Temperate Plants (theferns.info) - Amaranthus cruentus

   Original habitat obscure, probably tropical America. Vigorous annual to about 1m with branched stems and terminal flower spikes. Optimal temperature 22-28°C, tolerating 10-45°C but dying below 4°C. Prefers well-drained fertile soil in a sunny position, pH 5.5-7 preferred, tolerating 4.3-7.5. Sow in late spring where plants are to grow, or raise under glass and transplant after the last frosts; germination improves with warm soil and a drop in overnight temperature. EDIBLE PARTS: leaves cooked like spinach, mild-flavoured and rich in vitamins A and C, iron and calcium; seeds highly nutritious, eaten cooked, ground into flour or sprouted. First leaf harvest 30-50 days after sowing, continuing for up to 250 days more. CAUTION: on nitrogen-rich soils the plant concentrates NITRATES in the leaves.

These 4 sources are specific to this region. The full list of 9 sources behind this guide (African Journal of Agricultural Research (peer-reviewed; Appiah-Kubi et al. 2022, DOI 10.5897/AJAR2022.15985), FAO EcoCrop, GBIF and others) is in the references of our UK guide to blood amaranth; they describe the plant itself, which is the same wherever it grows.