The basics of growing turnips

Turnips are an ideal garden vegetable. In South Africa, they are best grown as a cool season crop for harvesting during early spring.

The turnip (Brassica rapa) is a root vegetable rich in vitamins A, C, B, B6, E and K. The leaves are sometimes eaten as ‘turnip greens’.

The common type of turnip is mostly white-skinned, apart from the upper 1cm to 6cm, which protrudes above the ground and is purple or red or greenish where sunlight has fallen on it. This above-ground part develops from stem tissue, but is fused with the root.

The interior flesh is entirely white. The root is roughly globular, 5cm to 20cm in diameter, and lacks side roots. Underneath, the taproot (the normal root below the swollen storage root) is thin and 10cm or more long; it is often trimmed off before the vegetable is sold. The leaves grow directly from the above-ground shoulder of the root, with little or no visible crown or neck.

The best time to plant turnips is in March and early April so that the plants can strengthen before the winter cold sets in and the first frost arrive. Turnips can tolerate moderate frost; indeed, as Gardening in South Africa (GSA) notes, many people say their flavour improves with colder weather. If, however, you are in an area with severe frost, use straw as a mulch to protect the roots from freezing.

In subtropical regions, turnips are grown from February to June during the winter months. In cooler summer regions, they are planted in August and September and harvested before the peak summer heat, which can spoil them.

CULTIVATION

Turnip seeds can be sown directly into garden beds, or started indoors in seedling trays and transplanted later. They prefer a sunny location with well-drained soil.