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: Marrow-Stem Kale

General Information

Marrow-stem kale is a biennial plant derived in cultivation from the wild cabbage. It grows around 100cm tall.
Marrow-stem kales are harvested for their edible leaves, which can be available even in the coldest of winters. The plant has fallen out of favour somewhat, and is not often cultivated for its edible leaves since these are coarser than other types of kale, and also coarser than other vegetables that can be imported from warmer areas in the winter.

Known Hazards

None known

Botanical References

Range

A cultivated form of B. oleracea.

Habitat

Not known in the wild.

Properties

Edibility Rating
Habit	Biennial/Perennial
Height	0.90 m
Pollinators	Bees
Self-fertile	Yes
Cultivation Status	Cultivated

Cultivation Details

Marrow-stem kale is a very hardy plant, tolerating temperatures down to about -15°c[]. It also tolerates high summer temperatures[].
A very easily grown plant, succeeding in full sun in a well-drained fertile preferably alkaline soil[, ]. Prefers a heavy soil[]. Succeeds in any reasonable soil[]. Shade tolerant, growing well on a north border[]. Succeeds in maritime gardens[]. Tolerates a pH in the range 4.2 to 8.3.
Marrow-stem kales are very cold tolerant and can be grown to provide a winter crop of leaves even in severe winter areas[, ].
There are several named forms[, ].

Edible Uses

Leaves - raw or cooked[, , ]. A strong cabbage flavour, they are delicious if used when fairly young though they can become tough with age[]. The leaves are usually available from autumn to late spring, and can be harvested all through the winter in all but the very coldest of seasons[].

Young flowering shoots - raw or cooked. Picked before the flowers open, they are fairly tender and can be used as part of a mixed salad. When cooked, they have a delicious flavour similar to sprouting broccoli[].

Medicinal

None known

Other Uses

None known

Propagation

Seed - sow in a seedbed outdoors in mid spring. Plant out into their permanent positions in the summer as space permits. Do not let the seedlings get overcrowded or they will soon become leggy and will not make such good plants. If your seedlings do get leggy, it is possible to plant them rather deeper into the soil - the buried stems will soon form roots and the plant will be better supported.