KOHL RABI
Sow: February to October
Plant: March to November
Harvest: January to December
January: Buy seed. Choose a purple-skinned variety like ‘Azur Star’ or ‘Kohlribi’ and a green one like ‘Noriko’ or ‘Olivia’.
February: Make the first sowings in a pot or tray. Cover with bubble wrap. Harvest plants sown last year – using those between golf-ball and tennis-ball size – but don’t let plants go to seed.
March: Seed sown now will germinate in around seven days. Growth will be faster than for earlier sowings. Plant out when seedlings are 5cm/2in tall. Allow 25cm/10in between rows and 15cm/6in between plants.
April: You can sow seed over the next few months if this is a favourite crop, but kohl rabi grows well outdoors during the summer, so save the polytunnel for early and late crops. Keep harvesting. Remove any plants that bolt. Continue to plant out when 5cm/2in tall.
May: Keep plants watered well. Harvest roots while small and tender.
June: Keep harvesting. Clear any plants that bolt.
July: Make the first sowings in pots for autumn and winter crops.
August: Sow for winter crops. Plant out seedlings when 5cm/2in tall. Keep roots damp in hot weather. Watch out for caterpillars on the leaves.
September: Still time to make late sowings.
October: Make the last sowing of the year, if temperatures are above 5˚C/41˚F.
December: Buy seed.
KOHL RABI TROUBLES
Slugs: March to October
Caterpillars: July to October
Damping off: February to April and September to November