Common Name: Black Mustard

General Information

Brassica nigra is an erect, annual plant, branched above, growing from 30 - 200cm tall, exceptionally to 300cm[].
The plant is often cultivated for its edible seed, though it is going out of favour because it rapidly sheds its seeds once they are ripe and this makes it harder to harvest mechanically than the less pungent brown mustard (Brassica juncea). The seed is used especially as a food flavouring, though it is also sown with the seeds of garden cress (Lepidium sativum) to provide mustard and cress, a salading eaten when the seedlings are about one week old. Black mustard is also grown as a medicinal plant. Black mustard is only suitable for hand-harvesting as a mustard crop, and is rapidly losing importance to Brassica juncea as a commercial crop[].
The plant has sometimes escaped from cultivation and become naturalized as a weed.

Known Hazards

When eaten in large quantities, the seed and pods have sometimes proved toxic to grazing animals[].

Botanical References

Range

The original habitat is somewhat obscure, probably the Mediterranean region. Occasionally naturalized in S.W. Britain[]

Habitat

Cliffs near the sea in S. W. England[].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Annual
Height	1.20 m
Pollinators	Bees, Flies
Self-fertile	Yes
Cultivation Status	Cultivated, Wild

Cultivation Details

Black mustard is adapted to a wide variety of climatic conditions. It is usually grown in the temperate and subtropical zones, being unsuited to wet tropical lowland areas but is able to be grown as a rainfed crop in tropical areas of low or moderate rainfall[, ]. The plant tolerates an annual precipitation of 300 - 1,700mm, an annual average temperature range of 6 to 27°c[].
An easily grown plant, black mustard is suited to many types of soils except very heavy clays, it grows best on light sandy loams, or deep rich fertile soils[]. Succeeds in full sun in a well-drained fertile preferably alkaline soil[]. Prefers a heavy soil in an open position[]. Another report says that it prefers a light well-drained soil and some shade in the summer[]. Succeeds in soils with a pH in the range of 4.9 to 8.2[].
This species is one of four species used to produce mustard.[] The other three (see their individual records for more information) are:-
Brassica carinata. Ethiopian mustard. This is scarcely used outside of the highlands of Kenya and Ethiopia.
Brassica juncea. Brown mustard. A major crop, largely replacing Brassica nigra in commercial cultivation and accounting for around 40% of the total market.
Sinapis alba. White mustard. The major mustard in cultivation, accounting for almost 60% of the market.
The plants are not very winter hardy so the seed is best sown in the spring when grown for its seed whilst it can be sown as late as late summer as a green manure crop.
The flowers have a pleasing perfume, though this is only noticed if several flowers are inhaled at the same time[].

Edible Uses

Mustard seed is commonly ground into a powder and used as a food flavouring and relish[, , , , ]. This is the black mustard of commerce, it is widely used as a food relish and as an ingredient of curry[]. Pungency of mustard develops when cold water is added to the ground-up seed - an enzyme (myrosin) acts on a glycoside (sinigrin) to produce a sulphur compound. The reaction takes 10 - 15 minutes. Mixing with hot water or vinegar, or adding salt, inhibits the enzyme and produces a mild bitter mustard[]. The seed can also be used whole to season pickles, curries, sauerkraut etc[, ]. Black mustard has a stronger more pungent flavour than white mustard (Sinapis alba) and brown mustard (B. juncea)[].

Leaves - raw or cooked[, , ]. A hot flavour, they can be finely chopped and added to salads or cooked as a potherb[]. The seedlings can also be used as a salading when about one week old, adding a hot pungency to a salad[, , , ].

Immature flowering stems - cooked and eaten like broccoli[].

An edible oil is obtained from the seed[, , ].

Medicinal

Mustard seed is often used in herbal medicine, especially as a rubefacient poultice[]. The seed is ground and made into a paste then applied to the skin[, , , ] in the treatment of rheumatism, as a means of reducing congestion in internal organs[, ]. Applied externally, mustard relieves congestion by drawing the blood to the surface as in head afflictions, neuralgia and spasms. Hot water poured on bruised seeds makes a stimulant foot bath, good for colds and headaches. Old herbals suggested mustard for treating alopecia, epilepsy, snakebite, and toothache[]. Care must be taken not to overdo it, since poultices can sometimes cause quite severe irritation to the skin[].
The seed is also used internally, when it is appetizer, digestive, diuretic, emetic and tonic[, , ]. Swallowed whole when mixed with molasses, it acts as a laxative[]. A decoction of the seeds is used in the treatment of indurations of the liver and spleen. It is also used to treat carcinoma, throat tumours, and imposthumes[]. A liquid prepared from the seed, when gargled, is said to help tumours of the 'sinax.'[]. The seed is eaten as a tonic and appetite stimulant[, , , ].
Hot water poured onto bruised mustard seeds makes a stimulating foot bath and can also be used as an inhaler where it acts to throw off a cold or dispel a headache[].
Mustard Oil is said to stimulate hair growth. Mustard is also recommended as an aperient ingredient of tea, useful in hiccup. Mustard flour is considered antiseptic[].

Agroforestry Uses:

The seed germinates freely, and quickly, growing away rapidly and making a very useful green manure. The plant is often grown for this purpose, producing a bulk suitable for digging into the soil in about 8 weeks[]. It is not very winter hardy, so is generally used in spring and summer. It does harbour the pests and diseases of the cabbage family, though, so is probably best avoided where these plants are grown in a short rotation and especially if club root is a problem.

Other Uses

A semi-drying oil is obtained from the seed,. As well as being edible it is also used as a lubricant, illuminant and in making soap[, , , ].

Mustard oil (allyl isothiocyanate) is used in commercial cat and dog repellent mixtures[].

Propagation

Seed - sow in situ from early spring until late summer as a green manure and in order to obtain a succession of crops. The main crop for seed is sown in mid spring.