How to grow kohl rabi

This unusual brassica isn’t widely available in supermarkets, so is well worth growing yourself. The swollen stem base, often called a bulb, can be green-, white- or purple-skinned, with pale green or white flesh inside. Kohl rabi is best harvested young, when tender, crisp and juicy, ideal for eating raw, grated into salads and coleslaws. It can also be lightly steamed, roasted or sautéed. It has a sweet flavour, like broccoli or mild turnip, to which it’s closely related. The leaves can also be cooked like greens. 

There are several varieties of kohl rabi to choose from, with green, white or purple skins. Purple varieties make a particularly attractive addition to the veg plot. They also tend to be hardier and slower to mature, ideal for later sowings and harvesting into autumn or even winter. All kohl rabi are white or pale green inside. 

F1 hybrid varieties tend to produce more vigorous plants and a reliable, consistent crop. It’s also worth choosing bolt-resistant varieties. For varieties that performed particularly well in RHS growing trials, see our recommended AGM fruit and veg. 

You can also see many crops, including kohl rabi and other brassicas, in the veg plots at all the RHS gardens, so do visit to explore how they’re grown, compare the varieties and pick up useful tips and inspiration. 

Kohl rabi seeds are available in garden centres and from online seed suppliers.  

Kohl rabi grows best a sunny spot with fertile, free-draining but moisture-retentive soil. Some varieties will also grow in partial shade, especially in summer. It dislikes acidic soil, so apply lime to raise the pH if necessary.

Weed the sowing site thoroughly, then add lots of garden compost – about two buckets per square metre/yard. Firm the soil, then rake to remove lumps and stones.

Kohl rabi is easy to sow outdoors in spring and summer. Seeds should germinate readily in under two weeks. Early sowings are best made indoors, as cold temperatures can cause plants to bolt.

Kohl rabi is a brassica, so it should be grown with its other cabbage relatives in crop rotations.

Kohl rabi is easy to look after, just water generously and protect from pests.

Harvest kohl rabi when young, between golf-ball and tennis-ball size, to enjoy them at their sweetest, with a mild flavour and succulent, crunchy texture. If you leave them to get too big, they lose their flavour and tenderness. Particularly in hot, dry weather, they can easily turn woody.

With repeated sowings, kohl rabi can be harvested from May through to November. Protect with cloches if you haven’t finished harvesting before wintery weather arrives.

To prepare kohl rabi, it’s usually best to remove the outer skin, then grate or chop finely to use in salads and coleslaw. Kohl rabi can also be lightly steamed, sautéed or added to stews. The young leaves can be cooked like kale.

Use kohl rabi as fresh as possible, when succulent and full of flavour and nutrients. It can also be kept in the fridge for a few days. In autumn, some varieties can be stored in a cool but frost-free place for up to several months.

Protect seedlings and young plants from slugs and snails.

In hot, dry conditions, kohl rabi can turn woody or bolt (flower prematurely), so water generously and regularly. Early and late crops are usually more successful, avoiding summer heat. Harvest when young and tender, especially if conditions turn dry. Cold temperatures can also cause bolting, so don’t sow too early outdoors, and harden off indoor-sown plants carefully.

Being a brassica, kohl rabi is potentially susceptible to the usual brassica pests and diseases, but as it’s quite fast growing, it’s generally less affected than many of its slower relatives. Cabbage caterpillars are the most likely problem, so either cover plants with insect-proof mesh or fleece, or check the leaves regularly for caterpillars and eggs.

Applying lime helps to combat clubroot disease, as does starting plants off in pots until they have a strong root system.