If you have started to create space from early crops in your allotment and are looking for something a bit different to grow as a late summer/autumn crop, why not try Kohlrabi? This tasty and nutritious crop comes in white, green and purple varieties – but, for late sowing, it is better to use the purple variety which can even be sown into August.
Create a firm seed bed in any reasonably light, fertile, free draining soil. Work in some general purpose compost or a handful of a suitable fertiliser. (The soil doesn’t have to be that deep as the bit we are interested in is the swollen stem growing above ground). Normally, the germination rate is high even in colder parts so sow thinly. Create a groove 1-2cm deep and sow one seed every 5cm (2″). Allow 25cm (10″) between rows. Seedlings should appear after about 10 days. Thin out to one plant every 25cm.
Kohlrabi is a brassica so is subject to the normal pests you might expect – particularly the cabbage white! But it is probably slightly more resistant and trouble-free than most other varieties in this family. They will need watering though – probably a little more than other plants.
Harvest the Kohlrabi when the swollen, round stem is about the size of a tennis ball. The leaves can be eaten as you might use Kale – but, beware, it is a strong flavour. The best bit is the swollen stem. Simply cut the top and roots off, peel the outer layer and either grate into a salad or into a slaw or cut into chunks and steam until tender (6-8 minutes). A favourite of mine is to then puree the steamed Kohlrabi – Yum.