How to Grow Kohlrabi in the UK

Kohlrabi is one of the fastest, most trouble-free brassicas you can grow in a UK garden — here's how to sow, grow, protect and harvest it for a crisp, mild-tasting crop from early summer through to winter.

Last updated 6 July 2026

Kohlrabi (Brassica oleracea, Gongylodes group) is the odd one out in the brassica family: instead of a head or leaves, it swells into a crisp, mild, turnip-like bulb that sits above the soil surface. It's quick to mature, takes up little space, and largely dodges the slower pest build-up that troubles cabbages and sprouts left in the ground for months. For UK growers looking for a fast, reliable crop to slot into gaps in a rotation, it's hard to beat.

What Is Kohlrabi and Why Grow It

The swollen part of a kohlrabi plant is actually a stem, not a root — which is why it sits proud of the soil rather than burrowing down like a turnip or swede. Both pale green and purple-skinned varieties are widely available in the UK, with crisp white flesh underneath in either case. Raw, it tastes like a milder, sweeter cross between broccoli stem and water chestnut; cooked, it softens into something closer to turnip. Because it matures in as little as 55–60 days from transplanting, it's one of the few brassicas you can realistically fit in as a catch crop between other vegetables.

Sowing Kohlrabi in the UK

Kohlrabi can be sown from March through to July for a continuous supply from early summer into winter. Sow thinly, 1cm deep, either direct into well-prepared soil or into modules for transplanting once seedlings have two or three true leaves. Seed germinates within 7–14 days at soil temperatures of around 10–25°C.

Thin or space plants to roughly 25–30cm apart each way. Crowding is the single most common reason kohlrabi bulbs come out small or misshapen, since the plants compete hard for light and moisture at close spacing.

Regional Timing: South vs North

In the milder south of England, an early sowing under cloches or fleece in March can bring on the first bulbs by late May. Further north and in Scotland, where soil stays cooler for longer, it's usually safer to hold off direct sowing until April, since a late cold snap can trigger premature bolting in young plants that have been checked by cold. Whichever region you're in, avoid sowing during the hottest weeks of high summer — a spell of heat and drought at seedling stage is the other common bolting trigger.

Watering and Feeding

Consistent moisture matters more for kohlrabi than for most brassicas, because any check in growth from drying out tends to push the bulb woody rather than just slowing it down. Water regularly through dry spells, particularly once bulbs begin to swell, and mulch around plants to help retain moisture. Our guide to building good vegetable soil in the UK covers how to get the moisture-holding structure right before you even sow.

Protecting Kohlrabi from Pests

Kohlrabi is vulnerable to the same pests that trouble cabbage and other brassicas: cabbage white butterfly caterpillars, flea beetle on young seedlings, and club root in badly affected soil. Because the crop matures so quickly, netting from the day of sowing or transplanting is the single most effective step — see our full guide to protecting brassicas from cabbage white butterfly for netting mesh sizes and timing. For a wider view of what else can go wrong in a UK vegetable bed, our garden problems, pests and diseases hub covers flea beetle and club root in more detail.

Harvesting Kohlrabi

Harvest as soon as bulbs reach golf-ball to tennis-ball size — typically 5–8cm in diameter, usually 55–60 days after transplanting. Cut the bulb just below soil level with a sharp knife rather than pulling, which can damage neighbouring plants. Purple varieties are often slightly slower and hardier than green ones, making them a good choice for the last sowing of the season heading into autumn.

Storing and Using Kohlrabi

Trimmed of its leaves, kohlrabi keeps for one to two weeks in the fridge salad drawer. For longer storage, bulbs lifted in autumn keep well for several weeks in a cool shed or clamped in slightly damp sand, similar to how you'd store swede or turnips. Peel away the tougher outer skin before eating — the flesh underneath is what you want, whether grated raw into slaws, roasted in wedges, or added to soups in place of turnip.