Common Name: Chinese Spinach

General Information

Amaranthus tricolor is a usually much-branched, vigorous, erect or ascending annual plant with a stout stem, growing up to 125cm tall.
A major leaf crop in tropical Asia, where t it is widely consumed and often sold in local markets[]. The plant is often cultivated in tropical and warm temperate regions, especially in Asia, for its edible leaves and seed[, ]. It is a very ornamental plant and is also often grown in the flower garden (where it is more commonly known as Joseph's Coat)[, ].

Known 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.

Botanical References

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Range

Probably originating in Tropical Asia, but widely cultivated and its original habitat is obscure

Habitat

A widely cultivated plant, it is not known in a truly wild situation, though sometimes occurs on cultivated land, flood plains, roadsides and wasteland as a non-persistent escape from cultivation[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Annual
Height	1.00 m
Pollinators	Wind, Self
Self-fertile	Yes
Cultivation Status	Cultivated, Ornamental

Cultivation Details

A plant originally from the tropics, it can be grown in a wide range of climates from the temperate zone to the tropics, where it thrives from near sea level to about 800 metres[]. It grows best in areas where annual daytime temperatures are within the range 22 - 30°c, but can tolerate 8 - 45°c[]. It can be killed by temperatures of 4°c or lower[]. It prefers a mean annual rainfall in the range 1,200 - 1,500mm, but tolerates 300 - 2,700mm[].
Prefers a light well-drained fertile soil in a sunny position[, ], though it does succeed in heavier soils[]. Dislikes dry conditions[]. Tolerates fairly acid soils[]. Prefers a pH in the range 5.5 - 7.5, tolerating 4.3 to 8[].
When grown as a leaf crop, the first harvest can be taken about 30 - 50 days after sowing the seed. So long as it is carried out regularly, and the plant prevented from flowering, cropping can then continue for a further 120 - 300 days[, ].
Continuous cropping may yield up to 20 kg/m2 marketable leaves per year[].
Plants are particularly susceptible to attacks by leaf-chewing insects[].
Plants should not be given inorganic fertilizers, see notes above on toxicity.
A polymorphic species[], it is often cultivated for its edible leaves, there are many named varieties[].
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[].

Edible Uses

Leaves - raw or cooked. Often used at the young seedling stage[, , ], they have a very mild flavour and are also cooked as a spinach[]. An excellent hot weather substitute for spinach[]. The leaves contain about 3.5% protein, 0.25% fat, 6.6% carbohydrate, 3.1% ash, 24mg iron per 100g, 464mg calcium per 100g, they are rich in vitamin A and have a fair content of vitamins B1 and C[]. On a zero moisture basis 100g of the leaves contains up to 2441mg calcium, 1008mg phosphorus, 51mg iron, 34mg sodium, 4475mg potassium, 37,623 micrograms beta-carotene equivalent, 0.68mg thiamine, 2.37mg riboflavin, 11.48mg niacin and 730mg ascorbic acid[].

The crisp interior of large stems makes a tasty vegetable[]. It can be eaten raw or cooked as an asparagus substitute[, ].

Seed - cooked[, ]. Very small, about 1mm in diameter[], but easy to harvest and very nutritious. 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 seed contains saponins[]. If this is the case it is probably best to either soak the seed for at least 12 hours and then rinse thoroughly before cooking or to give the seed a long slow cooking in order to destroy the saponins[].

Medicinal

The whole plant is astringent and diuretic[, ]. A decoction of the root is used with Cucurbita moschata to control haemorrhage following abortion[].

The seeds are said to have aphrodisiac properties[].

A decoction of very old plants is taken internally to improve vision and strengthen the liver.

Other Uses

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

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[]. A minimum soil temperature of 10°c is required for germination, germination is better at temperatures above 20°c[]. A drop in temperature overnight aids germination[].
Cuttings of growing plants root easily[].