Common Name: White Mustard

General Information

Sinapis alba is an erect, annual plant growing from a thin taproot; usually only branching in its upper part, it can grow 30 - 100cm tall[].
The plant is harvested from the wild for local use as a food and medicine. It is often cultivated for its seed, which is a source of oil; is used to make the condiment 'white mustard'; and is also used as a seed sprout in salads etc. It is the most important of the four species of mustard in cultivation, accounting for almost 60% of the market[]..

Known Hazards

The seed contains substances that irritate the skin and mucous membranes[].
The plant is possibly poisonous once the seedpods have formed[].

Botanical References

,

Range

Europe - Mediterranean. Naturalized in Britain[].

Habitat

A weed of arable and waste land, especially on calcareous soils[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Annual
Height	0.60 m
Growth Rate	Fast
Pollinators	Bees, Flies, Wind
Cultivation Status	Wild

Cultivation Details

White mustard is a quick-growing long-day annual which prefers temperate climates with some humidity[, ]. The plant can withstand high temperatures, but very hot days during flowering and ripening may reduce seed setting and lower the quality of the seed[]. It grows best where the annual precipitation varies from 350 - 1,790mm, annual temperatures from 5.6 - 24.9°c[].
Prefers a light well-drained soil[]. Succeeds on most soils when growing in a sunny position[]. For best production, the plant requires high nutrient soils with a high level of nitrogen, but it may be grown on a wide range of soils from light to heavy, growing best on relatively heavy sandy loamy soils[]. It is not suited to very wet soils[]. Succeeds in soils with a pH ranging from 4.5 - 8.2[].
A very fast growing plant, though it requires plenty of moisture for optimum growth[].
White mustard is sometimes cultivated, both in the garden and commercially, for its seeds which are a source of oil; the flavouring mustard; and also used as seed sprouts[, ]. There are some named varieties[].
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.
Brassica nigra. Black mustard is only suitable for hand-harvesting and is rapidly losing importance as a commercial crop.
Seed yields are usually a bit less than 1 tonne per hectare, though experimental plantings have suggested that up to 8 tonnes per hectare is possible[].
White mustard is sometimes also grown as a seed sprout, usually with cress seeds (Lepidium sativum) to supply mustard and cress. This is a mixture of the two types of sprouted seeds, used when about 7 - 10 days old[]. The mustard seed should be sown three days before the cress seed[].
The plant is not very deep rooted[], it self-sows freely when in a suitable site[].

Edible Uses

Leaves - raw or cooked[, , , ]. A hot pungent flavour, especially if eaten raw[]. Young leaves are used as a flavouring in mixed salads, whilst older leaves are used as a potherb[].

Seed - soaked in water then sprouted and eaten raw when the shoots are 3cm or more long[, , , ]. The seed takes about 4 days to be ready[]. A hot flavour, it is often used in salads. A nutritional analysis is available[].

The seed can be ground into a powder and used as a food flavouring[, , , ], it is the 'white mustard' of commerce[, ]. This is milder than the black mustard obtained from Brassica nigra[]. The 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 oil obtained from the seed can be used in cooking, as a flavouring in mayonnaise etc[]. The unrefined oil is rich in erucic acid, which is not appreciated in food oils[].

Medicinal

The seed is antibacterial, antifungal, appetizer, carminative, diaphoretic, digestive, diuretic, emetic, expectorant, rubefacient and stimulant[, , , ]. The seed has a cathartic action due to hydrolytic liberation of hydrogen sulphide[]. In China it is used in the treatment of coughs with profuse phlegm and tuberculosis, pleurisy[].
The seed is seldom used internally as a medicine in the west[]. Externally it is usually made into mustard plasters (using the ground seed), poultices or added to the bath water. It is used in the treatment of respiratory infections, arthritic joints, chilblains and skin eruptions etc[]. At a ratio of 1:3, the seed has an inhibitory action on the growth of fungus[].
Care should be exercised in using this remedy because the seed contains substances that are extremely irritant to the skin and mucous membranes[].

The leaves are carminative[].

Agroforestry Uses:

The plant can be grown as a green manure crop[, ]. It is very fast growing, producing a good bulk in just a few weeks from seed, but it is shallow rooted so does not do so well in dry periods[]. It is also susceptible to all the diseases of the cabbage family such as club-root so is best avoided if this is likely to be a problem[]. Often used as a late-sown green manure crop, some cultivars have been shown to decrease populations of beet cyst nematode in the soil[].
The flowers are a good source of nectar and very attractive to bees[].

Other Uses

The seed contains up to 35% of a semi-drying oil[]. It is used as a lubricant and for lighting etc[, , , ]. The seed is rich in erucic acid, which has several industrial applications[].

Propagation

Seed - sow in situ from early spring to late summer. Germination takes place in less than a week. The earlier sowings are for a seed crop, the later sowings are for edible leaves and green manure[].
When sowing seed for use in mustard and cress, the seed is soaked for about 12 hours in warm water and then placed in a humid position. Traditionally, it is sown in a tray on a thin layer of soil, or on some moist blotting paper, and the tray is placed in a warm dark place for a few days to encourage rapid and rather etiolated growth. The seedlings can then be placed in a lighter position for a couple more days to turn green before being eaten. The mustard seed should be sown about 3 - 4 days later than the cress for them both to be ready at the same time[].