Purple Amaranth, Red amaranth
Amaranthus cruentus

Family: Amaranthaceae

What it is like

Amaranthus cruentus is a ANNUAL growing to 2 m (6ft 7in). See above for USDA hardiness. It is hardy to UK zone 4 and is frost tender. It is in flower from July to September, and the seeds ripen from August to September. The species is monoecious (individual flowers are either male or female, but both sexes can be found on the same plant) and is pollinated by Wind. The plant is self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very acid soils. It cannot grow in the shade. It prefers moist soil.

Height (m): 2

Where it is found

Not known in a truly wild situation.

Original habitat is obscure, it was probably tropical America.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 4

Leaves - cooked as a spinach. The mild-flavoured leaves are rich in vitamins and minerals. Seed - very small but easy to harvest and very nutritious. They are eaten cooked or ground into a powder and used for making cakes etc. They can also be sprouted and used in salads. The seed can be cooked whole, and becomes very gelatinous like this, but it is rather difficult to crush all of the small seeds in the mouth and thus some of the seed will pass right through the digestive system without being assimilated. The flowers are used as a food colouring in ceremonial maize bread.

Seed: includes nuts, cereals, peas and beans.

Colouring: edible dyes

Medicine

Rating: 2

The plant can be cultivated from the tropics to the temperate zone. It grows best in areas where annual daytime temperatures are within the range 22 - 28°c, but can tolerate 10 - 45°c. It can be killed by temperatures of 4°c or lower. It prefers a mean annual rainfall in the range 2,000 - 2,400mm, but tolerates 500 - 4,000mm. Prefers a well-drained fertile soil in a sunny position. Requires a hot sheltered position if it is to do well. Prefers a pH in the range 5.5 - 7, tolerating 4.3 - 7.5. Often cultivated as a food crop and ornamental plant, it has escaped from cultivation in many areas and become naturalised as a weed of cultivated and disturbed ground. A fast-growing plant, the first crop of leaves can be harvested in 30 - 50 days from sowing the seed, and the plant can carry on being harvested for up to another 250 days. Grain yields usually range from 800-1200 kg/ha but with the use of fertilizers the yield can be raised up to 3 t/ha. This species is cultivated for its edible seed in many parts of S. America and in Japan. There is at least one named variety, 'Oeschberg' is a very productive plant, growing 1 metre tall and can yield up to 2.5 tonnes per hectare. This species is the most adaptable of the grain amaranths, it also flowers under a wider range of daylength hours than the other species. Plants are particularly susceptible to attacks by leaf-chewing insects. Plants should not be given inorganic fertilizers, see notes above on toxicity. Most if not all members of this genus photosynthesize by a more efficient method than most plants. Called the 'C4 carbon-fixation pathway', this process is particularly efficient at high temperatures, in bright sunlight and under dry conditions.

Other

Rating: 2

Yellow and green dyes can be obtained from the whole plant.

Dye: Plants that provide dyes.

Dynamic accumulator: Plants that gather minerals or nutrients from the soil and store them in a more bioavailable form and in high concentration in their tissues. Used as fertilizer or to improve mulch.

Food Forest: Plants for Edible Forest Gardens and Food Forests.

How it is grown

Prefers a well-drained fertile soil in a sunny position. Requires a hot sheltered position if it is to do well. Tolerates a pH in the range 4 to 7.5. Plants should not be given inorganic fertilizers, see notes above on toxicity. This species is cultivated for its edible seed in many parts of S. America and in Japan. There is at least one named variety, 'Oeschberg' is a very productive plant, growing 1 metre tall and can yield up to 2.5 tonnes per hectare. This species is the most adaptable of the grain amaranths, it also flowers under a wider range of daylength hours than the other species. Most if not all members of this genus photosynthesize by a more efficient method than most plants. Called the 'C4 carbon-fixation pathway', this process is particularly efficient at high temperatures, in bright sunlight and under dry conditions. In garden design, as well as the above-ground architecture of a plant, root structure considerations help in choosing plants that work together for their optimal soil requirements including nutrients and water. The root pattern is clumping, giving the plant a clumping habit. The predictable growth behaviour makes it easier to maintain without having to apply containment methods.

Propagating it: Seed - sow late spring in situ. An earlier sowing can be made in a greenhouse and the plants put out after the last expected frosts. Germination is usually rapid and good if the soil is warm. A drop in temperature overnight aids germination. Cuttings of growing plants root easily.

Best place to grow: Cultivated Beds;

Habit: Annual

Hardiness: 3-11

Growth:

Soil: Light (sandy), medium, heavy (clay)

Shade: No shade

Moisture: Moist

Things to keep in mind

No members of this genus are known to be poisonous, but when grown on nitrogen-rich soils they are known to concentrate nitrates in the leaves. This is especially noticeable on land where chemical fertilizers are used. Nitrates are implicated in stomach cancers, blue babies and some other health problems. It is inadvisable, therefore, to eat this plant if it is grown inorganically.

Its other names

Local names

Synonyms

A. hybridus cruentus. Thell.