Succeeds in full sun in most well-drained moisture-retentive fertile soils. Prefers a heavy soil and some shade. Dislikes very hot weather. Plants tolerate high rainfall and, although fairly deep rooted, are not very drought resistant. A form of B. juncea with curled leaves that has been selected in the Orient for its edibility. There are some named varieties. Plants in this group are fairly cold-tolerant and often stand the winter, they are then slow to bolt and can supply a good crop of leaves in the spring. Plants have a rooting depth of between 90 - 120 cm. A good bee plant.

Leaves - raw or cooked. A peppery flavor that can range from mild to hot, this is one of the most highly prized cooked vegetables in the Orient. The leaves can also be finely shredded and added to mixed salads. The protein extracted from the leaves mixes well with banana pulp and is well adapted as a pie filling. Flowers and young flowering stems - raw or cooked. Sweet and succulent. An edible semi-drying oil is obtained from the seed. The seed contains 25 - 30% oil. The seed is used as a mustard flavoring. It is the source of 'brown mustard', a prepared mustard that is milder than that produced from other species. 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. Black mustard comes from B. nigra and white mustard from Sinapis alba. The seed is also used whole in curries and pickles. They are often heated in oil to destroy their pungency and give them a nutty flavor. Sprouted seeds can be added to salads.

Seed - sow in situ from August to October. Spring and early summer-sown crops tend to run quickly to seed, though they can be eaten whilst still small. It is best not to sow the seed in very hot weather. There are about 5,660 - 6,000 per 0.01 kg (1/3 oz).

Not known in the wild.