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Amaranthus cruentus
Amaranthaceae FAMILY

Amaranthus cruentus

Amaranthus cruentus

Edibility
4/5
Medicinal
2/5

Safety & Hazards

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.

Cultivation Details

HabitAnnual
Growth—

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[1]. It can be killed by temperatures of 4°c or lower[1]. It prefers a mean annual rainfall in the range 2,000 - 2,400mm, but tolerates 500 - 4,000mm[1]. Prefers a well-drained fertile soil in a sunny position[2]. Requires a hot sheltered position if it is to do well[PFAF]. Prefers a pH in the range 5.5 - 7, tolerating 4.3 - 7.5[1]. 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[1]. 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[3, 4, 5]. 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[5]. This species is the most adaptable of the grain amaranths, it also flowers under a wider range of daylength hours than the other species[5]. Plants are particularly susceptible to attacks by leaf-chewing insects[6]. 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[7].

Propagation

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[8], but poor germination rates are experienced in cool or cold soils[9]. A drop in temperature overnight aids germination[8]. Cuttings of growing plants root easily[10]. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-20. <temperate.theferns.info/plant/Amaranthus+cruentus>

Pollinators

Wind, Self

References

  1. [1]Ecocrop — http://ecocrop.fao.org/ecocrop/srv/en/home ↩︎Basic information on a wide range of useful plants, plus details of environmental needs where available.
  2. [2]The New RHS Dictionary of Gardening. 1992. — Huxley. A. · MacMillan Press · 1992 · ISBN 0-333-47494-5 ↩︎Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
  3. [3]Flora of Japan. (English translation) — Ohwi. G. · Smithsonian Institution · 1965 · ISBN - ↩︎The standard work. Brilliant, but not for the casual reader.
  4. [4]The Ethno-Botany of Pre-Columbian Peru. — Towle. M. A. · Aldine Publishing Co. Chicago. · 1961 ↩︎A very interesting book covering quite a lot of information on plant uses in S. America although many of the plants are not suitable for temperate areas.
  5. [5]Cornucopia - A Source Book of Edible Plants. — Facciola. S. · Kampong Publications · 1990 · ISBN 0-9628087-0-9 ↩︎Excellent. Contains a very wide range of conventional and unconventional food plants (including tropical) and where they can be obtained (mainly N. American nurseries but also research institutes and a lot of other nurseries from around the world.
  6. [6]Edible Leaves of the Tropics — Martin. F. W.; Ruberte. R. M. & Meitzner. L. S. · Echo. USA. · 1998 · ISBN 0-9653360-1-8 ↩︎A terse guide, giving reasonable detail on the more common leaf crops and brief information on a wide range of lesser known plants.
  7. [7]Lost Crops of the Incas — Popenoe. H. et al · National Academy Press · 1990 · ISBN 0-309-04264-X ↩︎An excellent book. Very readable, with lots of information and good pictures of some lesser known food plants of S. America.
  8. [8]Growing from Seed. Volume 1. — Rice. G. (Editor) · Thompson and Morgan. · 1987 · ISBN - ↩︎Very readable magazine with lots of information on propagation.
  9. [9]The National Non-Food Crops Centre Crop Database — http://www.nnfcc.co.uk/crops/pd.cfm ↩︎An excellent on-line information source, with information on over 100 species (as of 2006) of plants being investigated as bio-crops.
  10. [10]Oriental Vegetables — Larkcom J. · John Murray · 1991 · ISBN 0-7195-4781-4 ↩︎Well written and very informative.
  11. [11]Pacific Island Ecosystems at Risk — http://www.hear.org/pier/scientificnames/index.html ↩︎A very good website detailing weed species that have been introduced into the Pacific Islands.
  12. [12]Protabase - Plant Resources of Tropical Africa. — http://www.prota.org ↩︎An excellent on-line database with detailed information on over 3,200 species of useful plants of Africa.
  13. [13]Traditional Vegetables in Benin — Achigan-Dako E. Et al · Darwin Initiative; International Foundation for Science · 2009 ↩︎Issued as a PDF on the Internet, it contains basic information on over 250 species of plants used for food in Benin.
  14. [14]Native American Ethnobotany — Moerman. D. · Timber Press. Oregon. · 1998 · ISBN 0-88192-453-9 ↩︎Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.
  15. [15]Nature's Colors - Dyes from Plants. — Grae. I. · MacMillan Publishing Co. New York. · 1974 · ISBN 0-02-544950-8 ↩︎A very good and readable book on dyeing.
  16. [PFAF]Plants for a Future — pfaf.org ↩︎