
Amaranthus dubius
Amaranthus dubius
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
A plant of the tropics, it has long been cultivated outside its natural range, succeeding from the temperate zone to most areas of the tropics, at elevations up to 1,200 metres. It grows best in areas where annual daytime temperatures are within the range 22 - 30°c, but can tolerate 12 - 45°c[1]. It can be killed by temperatures of 4°c or lower[1]. It prefers a mean annual rainfall in the range 2,100 - 2,400mm, but tolerates 700 - 4,000mm[1]. Prefers a well-drained fertile soil in a sunny position[2], though it can tolerate a wide range of conditions[3]. Requires a hot sheltered position if it is to do well[PFAF]. Prefers a pH in the range 6 - 7.5, tolerating 5.5 - 8.5[1]. Plants can bear their first crop of edible leaves within 30 - 50 days from sowing the seed[1]. If the plant is cut back and not uprooted, it may continue to produce further crops of leaves for 120 - 300 days[1]. This species most probably originated as a result of ancient hybridization between A. Spinosus and either A. Hybridus or A. Quitensis[4] The plant is sometimes cultivated in tropical areas for its edible leaves, there are some named varieties. The cultivar 'Claroen' is considered to be one of the best cultivars[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+dubius>
Pollinators
Wind, Self
References
- [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]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]Vegetables in the Tropics — Tindall. H. D. · MacMillan, Oxford. · 1983 · ISBN 0-333-24268-8 ↩︎An excellent, in-depth look at the main vegetable crops that can be grown in the Tropics, plus many less well-known plants.
- [4]Flora of N. America — http://flora.huh.harvard.edu/fna/ ↩︎An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses.
- [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]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]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]Growing from Seed. Volume 1. — Rice. G. (Editor) · Thompson and Morgan. · 1987 · ISBN - ↩︎Very readable magazine with lots of information on propagation.
- [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]Oriental Vegetables — Larkcom J. · John Murray · 1991 · ISBN 0-7195-4781-4 ↩︎Well written and very informative.
- [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]Plants for Human Consumption. — Kunkel. G. · Koeltz Scientific Books · 1984 · ISBN 3874292169 ↩︎An excellent book for the dedicated. A comprehensive listing of Latin names with a brief list of edible parts.
- [13]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.
- [14]Cornucopia II — Facciola. S. · Kampong Publications, California. · 1998 · ISBN 0-9628087-2-5 ↩︎The second edition of an excellent guide to the edible uses of plants, though it does not give any details of cultivation etc.
- [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.
- [PFAF]Plants for a Future — pfaf.org ↩︎