Common Name: Buckwheat

General Information

Fagopyrum esculentum is an erect, much-branched annual plant with hollow stems; it can grow from 60 - 120cm tall[].
The seed of buckwheat is an important subsistence food in parts of Asia, where the plant has a history of cultivation going back at least 1,000 years. The seed has gained acceptance as a healh food, whilst the plant also has edible leaves, some important traditional medicinal actions and supplies a dye. It is often grown on a garden scale, and also commercially on a small scale, for its edible leaves and seeds, whilst it is also commonly grown as a green manure crop and to restore worn-out soils.
Fagopyrum esculentum is cultivated in many parts of the world for its edible seed. It is a prolific producer of seed and these are often spread by animal activity. It easily escapes from cultivation and can become established as a weed of cultivated and waste ground, though it is easy to control and does not usually become a pest.

Known Hazards

Buckwheat seed is considered to be one of the most important food allergens. It also contains compounds which can cause irritating skin disorders (‘fagopyrism’) mainly in sheep and pigs and occasionally in humans, especially in cases where there is heavy consumption and also exposure to sunlight[]. Fagopyrism has also been observed in humans after consumption of buckwheat honey. It may also affect cattle when fed pure buckwheat silage[].
The plant has caused photosensitivity in some people, only the dehusked grain is considered to be safe.

Botanical References

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Range

Probably originating in southern China, the plant is cultivated in many temperate areas where it sometimes escapes and is found wild.

Habitat

Waste ground as an escape from cultivation[]. Its original habitat is obscure.

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Annual
Height	1.50 m
Growth Rate	Fast
Pollinators	Bees, Flies
Self-fertile	No
Cultivation Status	Cultivated

Cultivation Details

Fagopyrum esculentum is a plant of the temperate and subtropical zones, though it can also be grown at higher elevations, generally above 1,500 metres, in the tropics[]. It grows best in areas where annual daytime temperatures are within the range 17 - 27°c, but can tolerate 7 - 40°c[]. It is very sensitive to frost[]. It prefers a mean annual rainfall in the range 700 - 1,000mm, but tolerates 400 - 1,300mm[].
A very easily grown plant, it prefers dry sandy soils but succeeds in most conditions including poor[, , ], heavy[] or acid soils[] and even sub-soils[]. It prefers a pH in the range 5 - 6.5, tolerating 4.4 - 7.5[].
Prefers a cool moist climate, but it also succeeds in dry and arid regions[]. Hot drying temperatures and drying weather at blooming time blast the flowers and prevent seed formation[]. The plant has a poorly developed root system that makes it rather sensitive to drought[].
Buckwheat is a fast-growing plant that can reach its full height within 4 - 6 weeks. Flower formation starts 20 days after emergence, the plant continuing to flower until complete senescence and death of the whole plant. After the onset of flowering, the leaves and stems continue to grow while the fruits develop, hence seed ripening is very uneven, making harvesting difficult. From the middle of the flowering period onwards, when the leaf area has reached its maximum, further growth of the vegetative parts is slow, and producing ripe seed becomes the main focus of the plant. The seed is ready for harvesting 70 - 130 days after emergence, depending on cultivar and ecological conditions[, , , ].
The seed is harvested when most of it (at least 75%) is mature and most leaves have yellowed and dropped. The crop is harvested by mowing, after which the stems are bundled and put in heaps to dry. Farmers prefer to harvest early in the morning or late in the afternoon, or even at night, when the plants are slightly damp from dew, to reduce grain shattering[].
Average seed yield in the United States is 0.9 - 1 tonne per hectare; in Kenya it is 1 tonne; and in Russia 1 - 1.3 tonnes; but up to 4 tonnes can be obtained[].
The seed ripens irregularly over a period of several weeks so it is difficult to harvest[].
Plants have poor frost resistance but they are disease and insect resistant[]. They inhibit the growth of winter wheat[, , ].
There are some named varieties[].
The flowers have a pleasant sweet honey scent[] and are extremely attractive to bees and hoverflies[, ].

Edible Uses

Leaves - raw or cooked like spinach[, , ]. Not that wonderful raw, they improve somewhat with cooking[]. The leaves are rich in rutin[] (see below for more details) and so are a very healthy addition to the diet[].

Seed - raw or cooked. A nutty flavour, though it has a somewhat gritty texture that is not universally liked[]. It can be cooked like rice[]. The seed can be soaked overnight in warm water then sprouted for a few days and added to salads[]. It can also be ground into a powder and used as a cereal[, , ], when it can be made into pancakes, noodles, breads etc or be used as a thickening agent in soups etc[, ]. It is popular for use in mixtures with wheat, barley or rye flour to improve the taste and nutritional value of bread and other foodstuffs. Up to 30% of buckwheat flour may be mixed in wheat dough for baking bread[]. Due to the absence of gluten, buckwheat is suitable for the diet of people with coeliac disease[]. Rich in vitamin B6[].
An excellent beer can be brewed from the grain[].

Fresh leaves and inflorescences are used for the industrial extraction of rutin, which is applied to strengthen the inner lining of blood vessels (however, it is rather the related species Fagopyrum tataricum (L.) Gaertn., which is commonly grown for rutin production). Rutin is also industrially used as a natural pigment, antioxidant, stabilizer, food preservant and absorber of UV light.

Medicinal

Buckwheat is a bitter but pleasant tasting herb that is frequently used medicinally because the leaves are a good source of rutin[].
The bioflavonoid rutin is obtained from all above-ground parts of the plant. Rutin has been shown to be useful in the treatment of a wide range of circulatory problems. It is a capillary tonic that strengthens the inner lining of blood vessels, dilates the blood vessels, reduces cholesterol levels, reduces capillary permeability and lowers blood pressure. In addition, it is strongly antioxidant, diuretic, anti-inflammatory and antispasmodic. It has also been shown to help inhibit cancer-forming cells and protects the cells against the harmful effects of radiation[, , ].

The leaves and shoots of flowering plants are acrid, astringent and vasodilator[, , ]. It is used internally in the treatment of high blood pressure, gout, varicose veins, chilblains, radiation damage etc[, , ]. It is best used in conjunction with vitamin C since this aids absorption[]. Often combined with lime flowers (Tilia species), it is a specific treatment for haemorrhage into the retina[]. The leaves and flowering stems are harvested as the plant begins to flower and are dried for later use[]. They should be stored in the dark because the active ingredients rapidly degrade in the light[]. Some caution should be exercised in the use of this herb because it has been known to cause light-sensitive dermatitis[].

A poultice made from the seeds has been used for restoring the flow of milk in nursing mothers[].

An infusion of the herb has been used in the treatment of erysipelas (an acute infectious skin disease)[, ].

A homeopathic remedy has been made from the leaves[]. It is used in the treatment of eczema and liver disorders[].

Agroforestry Uses:

A very good green manure plant, it can be used to reclaim badly degraded soils and subsoils[, , , , ].
The flowers are extremely attractive to bees and hoverflies[, ].

Other Uses

A blue dye is obtained from the stems[, ].
A brown dye is obtained from the flowers[].

Propagation

Seed - sow from the middle of spring to early summer in situ. The seed usually germinates in 5 days[]. The earlier sowings are for a seed or leaf crop whilst the later sowings are used mainly for leaf crops or green manure.