Kohl Rabi
Brassica oleracea gongylodes
Family: Brassicaceae or Cruciferae
What it is like
Brassica oleracea gongylodes is a BIENNIAL growing to 0.5 m (1ft 8in) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 5 and is not frost tender. It is in flower from May to August, and the seeds ripen from July to September. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees. The plant is self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in heavy clay soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil and can tolerate drought. The plant can tolerate maritime exposure.
Height (m): 0.5
Where it is found
Not known in the wild.
A cultivated form of B. oleracea, not known in the wild.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 3
Leaves - cooked. Used as a vegetable, though the quality is not as good as cabbage. The young leaves can also be added to salads, though some people find them difficult to digest. A nutritional analysis is available. Stem - raw or cooked. The plant produces a swollen stem just above ground level, and this is often used as a root vegetable. It has a mild cabbage flavour, when finely grated it makes a good addition to mixed salads and, when cooked, is an excellent vegetable. It is best eaten whilst fairly small and tender, between golf ball and tennis ball size. It becomes coarse with age. A nutritional analysis is available.
Stem: this often intergrades into leaves.
Medicine
Rating: 1
The leaf is digestive and tonic.
Digestive: Aids digestion.
Tonic: Improves general health. Slower acting than a stimulant, it brings steady improvement.
Other
Rating:
How it is grown
Succeeds in full sun in a well-drained fertile preferably alkaline soil. Succeeds in any reasonable soil, though it is best not grown in an acid soil. Tolerates a pH in the range 4.5 to 7.5. Prefers some shade and plenty of moisture in the growing season. Established plants are drought tolerant but the best stems are formed when the plant does not go short of moisture. Succeeds in maritime gardens. Very winter hardy, kohl rabi withstands severe frosts and so can be left in the ground all winter in most areas and be harvested as required. The young growing plant, however, is sensitive to low temperatures and a week at 10°c will cause the plants to bolt. It grows best at a temperature between 18 and 25°c. Kohl rabi is often cultivated for its edible swollen stem which can be available almost all year round from successional sowings. There are several named varieties and stem colour can range from white to green and purple. Green forms are faster to mature and so more suitable for early sowings, the purple forms are hardier and later to mature, they are used mainly for winter crops. Very fast growing, the stems of some cultivars can be harvested 6 - 8 weeks after sowing. The plant is more tolerant of drought and high temperatures than turnips, which it resembles in flavour, and so it is often grown as a substitute for that species. Grows well with onions, beet and aromatic herbs which seem to reduce insect predations. Plants also grow well with cucumbers, the roots of each species occupying different levels in the soil. Grows badly with strawberries, runner beans and tomatoes.
Propagating it: Seed - sow April to August in situ. Earlier sowings can be made under cloches.
Best place to grow: Cultivated Beds;
Habit: Biennial
Hardiness: 4-8
Growth: Fast
Soil: Light (sandy), medium, heavy (clay)
Shade: Semi-shade, no shade
Moisture: Moist
Things to keep in mind
Its other names
Local names
Synonyms
B. caulorapa. Pasq.