Turnips don’t grow quite as well for us as their bigger cousins neeps (swedes/rutabaga), but they’re fast growing and can be sown for around half the year.
Eaten at six to 10 weeks old, when they’re golf to tennis ball sized, they’re excellent for pepping up dishes made from stored vegetables as well as being delicious with early crops of baby carrots and new potatoes.
Turnips prefer deep, fertile soil in open, sunny locations. Acidic soils such as ours are limed as turnips do best when the pH is between 6.0 and 6.5. The best time to lime is in the autumn or early winter before sowing.
Do not sow turnips sown in freshly manured soil or they will fork. High acidity results in club root.
In warmer areas, it is possible to sow turnips in February provided the soil temperature is above 4-5ºC and the seedlings are protected from light frosts. We’ve tried February sowings, achieving some success with germination, but hard frosts invariably kill the seedlings even when they’re covered with fleece.
Our best results have come with sowing from mid-March onwards, picking up through April, May and June. Growth tends to fall away if the soil temperature rises above 15ºC but this is rare in north-east Scotland. We sow in to July but not August as late sowings are invariably destroyed by early frosts.
We rake the turnip beds to a fine tilth before sowing.
The corner of a hoe is used to draw 10mm deep rills with the corner of a hoe at 30cm spacings, with the seed scattered along the drills and covered with a 50:50 sand/compost mix. This is easier for the seedlings to pass through, provides them with nutrients and marks the rows. The back of a hoe blade is used to lightly firm the sand and compost before the seeds are watered in.
When the seedlings are tall enough to be pinched, they’re thinned to 75mm spacings and a few weeks later to 150mm spacings. The soil is watered well to prevent the roots becoming woody and stringy.
Frequent weeding is essential to maintain good growth, but if using a hoe keep the blade shallow in the soil as turnips don’t like having their roots disturbed.
We pick turnips quite frequently as they should not be allowed to grow larger than tennis balls. Larger turnips can be tough and stringy, plus the flavour becomes quite unpleasant. We don’t freeze or store turnips, preferring to eat them fresh, but some sources say they can be frozen or lifted and stored in sand-filled containers in frost-free sheds.
It’s not possible to overwinter turnips in the ground in our conditions as they freeze, split and turn to mush once thawed. (Neeps, on the other hand, can be overwinter in the ground, beneath a layer of straw.)
The turnip varieties that we’ve tried include:
- Golden Ball is very good early and late in the growing season. The seedlings are the most hardy of the turnips we grow, while the mature plants survive light frosts with little or no damage. The roots are soft, yellow and have a good flavour.
- Purple Top Milan is good early in the season as it germinates well in cool soil. The seedlings aren’t quite as hardy as Golden Ball, but mature plants usually survive light frosts with little or no damage. The roots are white and particularly delicious.
- Noir d’Hiver is an unusual looking black-skinned turnip with a long, cylindrical root. Seed catalogues list them as frost resistant, but we’ve not found them to be as robust as Golden Ball or Purple Top Milan. The flavour is noticeably sweeter to those two varieties, making Noir d’Hiver quite child friendly.
- Snowball is a sweet, white turnip that grows particularly fast. However, we lost many to frost damage in the three years we sowed it and no longer grow it.
Club root can be a problem with turnips, as with other brassicae, but we’ve had almost no experience of it due to good soil management. The main pests we’ve encountered are cabbage root fly and cutworms. Crop rotation, on a four-year cycle, as well as covering the plants with fleece keeps losses low.
We’ve not experienced problems with flea beetle, although this could be down to the use of fleece to counter cabbage root fly and cutworms. Slug damage is minimal as we use nematodes for their control.
- Pests of Swedes and Turnips—Their Management and Control (sac.ac.uk)
- The better turnip: White Japanese turnips (mnn.com)
- Succession Planting – Twice the harvest, half the space (smallspacebigharvest.com)