Turnips and swedes are versatile roots that can be mashed, roasted, added to stews, or even made into gnocchi. The vibrant green leaves of turnips are also edible, and some gardeners sow a row or two especially for their tasty tops! Here, experienced allotment grower Lee Senior shares his practical advice on growing these traditional vegetables.
Browse our full range of turnip and swede seeds for inspiration.
What are the best varieties of turnips and swedes?
My ‘go-to’ turnip variety is ‘Purple Top Milan’. Ultra-reliable, I think it’s also the most visually attractive turnip due to its purple crown. It has a delicious flavour and the seeds can be sown over a long period – from late March to early August.
Another favourite of mine is the all-white Turnip ‘Snowball’. It can be sown quite early in the year and has a slightly milder, sweeter taste than some turnips. It’s ideal for harvesting while still young, when it can be eaten raw in salads.
For something a little different, F1 Turnip ‘Sweetbell’ fits the bill! This juicy, fresh-tasting variety has a subtle flavour that hints at melon. Quite unlike traditional options, it’s a good alternative for anyone who doesn’t necessarily want a strong turnip. Another benefit is that the leaves are smooth, making them excellent for salads.
For me, the best swede is the long-established RHS AGM winner, Swede ‘Ruby’. The creamy yellow flesh has a remarkably sweet flavour, and it’s tolerant of winter cold, so can be kept in the ground over winter and harvested as late as the end of February! This variety also has some resistance to powdery mildew.
Swede ‘Invitation’ is another reliable, time-served variety that’s helpfully resistant to clubroot and powdery mildew. It has good flavour and stores well over winter. An easy variety to grow, this is a good choice for beginners.
How and when to sow turnips
Image: Turnip ‘Purple Top Milan’ Seeds from Suttons
There are several different ways to sow turnips, depending on the time of year. Early sowings can be made under glass during late winter or early spring in a heated propagator, cold greenhouse or on the windowsill.
Sow the seed thinly in trays of seed compost, 1.5cm deep, and lightly cover. The seeds will germinate in about 5-7 days and can be transplanted when the true leaves appear. Harden-off and plant out in April, avoiding too much root disturbance.
Turnips can also be sown in clusters under glass. Using modular trays, group several seeds together in each small block or square. When they emerge, the clump of seedlings can then be planted out as one square block without disturbance. The resulting turnips grow to a smaller size, and are harvested as such. The sweeter flavour is delicious in salads.
Turnips are also ideal for container sowing and growing. Early varieties can be started-off at the beginning of March under a cloche in a sunny location. They will grow quickly once they get going in spring as the weather warms up.
The easiest way to sow turnips is directly outside where they are to grow on to maturity. Wait until the soil is sufficiently warm (between mid-April and mid-August) and then sow your seeds into pre-watered drills at a depth of just over 1cm. Lightly cover with soil and gently firm. Leave 15-20cm between each plant and 30cm between rows and prepare the soil to a fine tilth in advance. This method avoids root disturbance and the need to harden-off seedlings grown under glass.
Turnips grow and mature quite quickly (in around three months) depending upon weather and ground conditions. To ensure a regular supply, sow successionally every 2-3 weeks. This will provide turnips from June through to December.
How and when to sow swedes
Image: Swede ‘Invitation’ seeds from Suttons
Swedes are related to turnips and have similar needs, but they’re a little more exacting with their requirements. Much slower growing, they require a longer growing season and are less suited to early spring sowings than turnips.
Swedes can be sown under glass from late-March and then transplanted after hardening off – giving you a late summer crop. However it’s more usual to sow the seed in May for a winter harvest.
The most straightforward way to grow swede is by direct sowing the seeds into a pre-watered drill. Sow the seeds at a shallow depth of just over 1cm, lightly cover with fine soil, and gently firm. Space the rows 45-50cms apart. This method avoids the need for hardening-off seedlings grown under glass. Swede is a slow-growing plant, taking around 4-5 months to mature, depending on your preferred size. I like to make my main sowing in early May for harvesting as a winter crop.
I’m not a fan of growing swedes in containers. They’re rather slow to mature, and are unlikely to reach a decent size. Unlike turnips, cluster-sowing doesn’t work either. The good news is, you can grow them in raised beds.
How to care for turnips and swedes
Image: Swede ‘Ruby’ seeds from Suttons
Turnips and swedes are both generally quite easy to grow. However it’s worth remembering that they’re part of the brassica family and, as such, are susceptible to the same pests and diseases. These include clubroot, cabbage root fly, flea beetles and the caterpillars of the cabbage white butterfly. Swedes can also be susceptible to powdery mildew. While that sounds like a long list – please don’t let it put you off! They’re not at all difficult, and both vegetables are pretty resilient.
Every single year that I’ve grown turnips and swedes, flea beetles have attacked the young outdoor seedlings and plants. Tiny holes in the leaves are the tell-tale signs of attack. The good news is, healthy plants aren’t usually too badly affected over the longer term, and should generally recover to produce a good crop.
Caterpillar attacks are a little less likely on root crops than on larger greens such cabbages, broccoli and sprouts, but they can happen. Cover with anti-butterfly netting or use nematodes to prevent an attack. You can also use the finger and thumb method to control the eggs which are usually highly visible.
With regards to clubroot, try to choose resistant varieties like Swede ‘Invitation’ or grow the plants in raised beds of compost. Turnips are quick to mature so, in my experience, clubroot is quite rare.
The key thing to get right is watering. Both turnips and swedes require plenty of moisture during dry spells. Swede roots can split and are prone to becoming a little more woody if they’re subjected to prolonged dry spells. Swedes are also more likely to succumb to powdery mildew if they’re stressed due to drought. It’s best to try to keep both turnip and swede plants moist where possible, as the quality of the mature roots is determined by this. Keep on top of any weeds so they don’t take moisture from the plants.
Both turnips and swedes grow best in soil containing some well rotted organic matter or leafmould. This will help slowly feed the plants and assist with moisture retention. They also enjoy a soil containing some lime content, and a PH of between 6.5 and 7.
How and when to harvest turnips and swedes
Image: Turnip ‘Silky Sweet’ F1 seeds from Suttons (© Branded Garden Products)
Harvest turnips when they’re about the size of a golf ball, or a little smaller if required for salads. The smaller they are when pulled, the sweeter they will be. If you plan to cook them, they can be allowed to get a little larger. Inevitably, larger roots will become woody and more bitter in flavour if they’re left too long before pulling.
Swedes are generally harvested at a much larger size than turnips, somewhere between the size of a tennis ball and a football. Some varieties can go a little woody with age.
Twisting the tops off the plants when harvesting is useful, as this helps the roots store a little longer. However if you’re using them within a few days, cutting the tops off is equally fine.
In well-drained veg patches or raised beds, both turnips and swedes can be left in the ground until needed if the weather is mild and slugs aren’t a problem. Swedes are hardier than turnips and can be relied upon as a winter staple in many cases. I’ve seen them survive frozen ground without any damage, so I prefer to leave them outdoors in situ until I require them. But if you garden in heavy clay, harvest your roots and store them in boxes of soil or sand for use over winter. Alternatively, both swede and turnips can also be stored in a cool, dark room after harvesting. They should remain usable for several weeks in this condition.
We hope we’ve inspired you to try growing your own turnips and swedes. Find more of Lee’s practical, hands-on, vegetable growing advice over at his monthly allotment pages. You can also follow Lee on his Instagram page: @lee_senior_gardening.
Lead Image: Swede ‘Gowrie’ from Suttons
