When to plant Kohlrabi in the UK

Sow seeds around mid-April to mid-May in drills or short blocks, about 1.5–2 cm deep. Sow a little at a time every 21 days for a steady run of crops rather than one large batch.

From early May, thin seedlings so the strongest plants are left at 25 cm apart. Keep the soil lightly moist so the remaining plants keep moving without checking.

From mid-April, cover the bed with fine mesh to keep out cabbage white butterflies and pigeons. Fit brassica collars snugly at the stem base to cut cabbage root fly damage, and check the netting after strong wind.

From early May to early August, feed every 28 days with a nitrogen-rich fertiliser and keep the bed evenly watered. A steady feed helps the swollen stems bulk up without turning pithy.

Start lifting or cutting from mid-June once the swollen stems are about 5–8 cm across and still tender. Pick over the crop through early August, because older plants soon become woody and splitting is more common after dry spells.