This species has been cultivated as a food crop for many hundreds of years and, in that time, several quite distinct forms have arisen. The nomenclature of these forms is confused, to say the least, and by no means universally accepted. We have followed the treatment used by GRIN, though it is very likely to be revised in the future[].

Common Name: Rape Kale

General Information

Rape Kale is an annual to biennial plant growing up to 120cm tall.
The plant is cultivated as a vegetable crop - unlike the swede or rutabaga, this plant does not have a swollen root and is grown mainly for its edible leaves.

Known Hazards

The oil contained in the seed of some varieties of this species can be rich in erucic acid which is used in industry but is toxic if consumed. However, modern cultivars have been selected for culinary use which are almost free of erucic acid[].

Botanical References

Range

Europe - Mediterranean. Naturalized in Britain[].

Habitat

Banks of streams, ditches and arable fields in Britain[].

Properties

Edibility Rating
Medicinal Rating
Habit	Annual/Biennial
Height	1.20 m
Pollinators	Bees, Self
Self-fertile	Yes
Cultivation Status	Cultivated

Cultivation Details

Very young plants are susceptible to cold damage, -4°c either killing or injuring seedlings, whereas -2°c has no affect when the plants are more than one month old[].
Succeeds in full sun in a well-drained fertile preferably alkaline soil[]. Succeeds in any reasonable soil[]. Prefers a heavy soil and cool moist conditions[, ]. Tolerates a pH in the range 4.2 to 8.3.
Plants are intolerant of root disturbance and so should not be transplanted[].
Rape kale is 70% self-pollinating and 30% cross-pollinated. Even if wind and insects are absent, seed are still produced. Yield increases with the presence of honeybees[].
This species is closely related to Brassica rapa[].

Edible Uses

Leaves - raw or cooked[, , ]. Added to salads or used as a potherb[].

Immature flowering stems - cooked in much the same way as broccoli[].

An edible oil is obtained from the seed, it is used mainly for cooking purposes, but also for salads[, , , , ]. Some caution is advised, see the notes above on toxicity.

The sprouted seed is often used as the mustard part of mustard and cress. Eaten in salads[, , , ].
The seed is ground into a powder and used as a mustard flavouring[].

Medicinal

The root is emollient and diuretic[]. The juice of the roots is used in the treatment of chronic coughs and bronchial catarrh[, ].

The seed, powdered, with salt is said to be a folk remedy for cancer[].

Rape oil is used in massage and oil baths, it is believed to strengthen the skin and keep it cool and healthy. Combined with camphor it is applied as a remedy for rheumatism and stiff joints[].

Agroforestry Uses:

The growth of this plant is inhibited by field mustard and hedge mustard growing nearby[, ].

Other Uses

The seed contains up to 45% of an edible semi-drying oil. Since it is grown as a leaf crop, the plant does not normally get utilized for its seeds. When available, it can be used as a luminant, lubricant, in soap making etc[, , , ]. It is probably best not to use it for food - see the notes above on toxicity[].

Propagation

Seed - sow spring in situ.