How to grow swedes

Swedes (short for Swedish turnips) are extremely hardy and do well in cool, damp climates. These slow-growing, moisture-loving root vegetables are harvested in autumn and winter, and have a sweeter flavour than turnips.

The period of time when an individual plant is in active growth. This will depend on the local climate and light levels, and can vary between different plants, although it is broadly from spring to autumn.

growing season

There are several swede varieties to choose from, forming large, rounded, purple-topped roots with creamy-white or pale yellow flesh.  

Sowing times vary, so check seed packets. F1 hybrid varieties tend to produce more vigorous plants and a reliable, consistent crop. Some varieties keep better than others, so if you’re planning on harvesting right through winter, choose a variety that won’t turn woody and stores well. Many varieties are resistant to clubroot disease and powdery mildew. 

Varieties with an RHS Award of Garden Merit (AGM) performed well in trials, so are always reliable choices – see our list of AGM fruit and veg for recommended varieties. 

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

Swedes can be sown outdoors from mid-spring to early summer, or from late spring in colder parts of the UK. Alternatively, you can start them off indoors to get a head start, then transplant outside after a few weeks. 

If you sow several small batches a few weeks apart, you can spread your harvests over a longer period.

Swedes are brassicas, so should be grown alongside their cabbage relatives in crop rotations. This helps to avoid any build-up of pests and diseases in the soil. 

Swedes are not suitable for growing in containers unless harvested when young.

Swedes are a long-term crop, taking up to six months to mature. Keep the soil moist and weed-free throughout, and protect the plants from pests.

Swedes are very versatile and can be harvested at whatever size you prefer – as baby veg after only a few weeks, as young roots about 5cm (2in) in diameter, or, more usually, when 10–15cm (4–6in) across. They can also be left to grow larger, as long as you choose a variety that won’t turn woody.

Swedes are usually ready to harvest from early autumn onwards, but you can leave them in the ground into winter or even early spring, lifting whenever needed. They are particularly valued as a winter crop, when little else is available.

Although swedes are hardy, it’s best to cover the crop with straw or fleece before winter. If the ground is likely to freeze, lift the roots and store in containers of soil or potting compost in a frost-free shed or garage.

Swedes are delicious roasted or mashed with butter, or used in soups, stews and similar. They are rich in vitamins, calcium and magnesium.

Swedes need plenty of water to grow well and shouldn’t be allowed to dry out, as the roots can split or turn bitter, and the leaves may develop powdery mildew.

Seedlings and young plants are vulnerable to slug and snail damage.

As swedes are brassicas, they are susceptible to cabbage pests and diseases, including cabbage root fly, caterpillars and pigeons, so are best grown under insect-proof mesh. Clubroot can be a problem too, especially in acidic soil, so apply lime the winter before sowing if you’ve had this fungal disease in your plot before, and choose a resistant variety.