Kale used to be the poor relation of the brassica family, outclassed by cabbages, Brussels sprouts and broccoli. But every trendy supermarket and farm shop is selling it as a super food now, and at a super price!
I find it’s the easiest brassica to grow and when I lived in the Northamptonshire wolds (where the knife-like wind cuts in from The Urals) it was the only brassica that came through the severe winters. It could also be harvested throughout winter, whereas purple sprouting broccoli (if it survived) was never ready before mid-March.
When to plant
Plant out the young kale plants by mid-summer (50cm/ 20in apart in rows 75cm/ 30in apart) and they should soon become statuesque.
Where to plant
All brassicas want to grow for you but kale, like all the others, prefer fertile, well-drained soil.
If your allotment has heavy soil build a simple raised bed by mounding up the soil to a foot high, or nine inches (20 -30 cm).
How to plant
Sow kale seeds in drills, in modules or in trays in spring - usually late March. I prefer modules because they make individual plants which are easy to handle and quick to grow away.
Net them as soon as you’ve planted them to keep away cabbage white and small white butterflies - using 4ft high canes topped with small pots to support the small gauge netting. If their leaves touch the net the butterflies still lay their eggs - so aim for a tantalising gap.
Kale’s big advantage (apart from extreme hardiness) is a resistance to club root (Plasmodiophora brassicae), a fungal disease many allotment plots harbour. The roots become swollen and the plants become stunted. So if you’ve failed with some other brassicas - have a go with kale.
If you haven’t got club root the best way to avoid it in future is to raise your own brassica plants and never to buy any in. If you have got it, rest the ground from all brassicas for seven years and pray!
The best varieties of kale
'Dwarf Green Curled'
Bright-green crinkled leaves - a bit thistly to eat - but it shrugs off aphid attack and is less popular with caterpillars - although not immune.
Handsome red crinkled leaves on a taller plant. Not as good to eat a as the green one - but very ornamental in winter.
'Cavola Nero' or Black Tuscan kale
Rather like a miniature palm in structure with a radiating ruff of dark-green, linear leaves, its common name (palm cabbage) is apt. The mildly flavoured leaves are delicious eaten steamed or boiled with butter and it can be picked earlier than others - often in early autumn. Like all brassicas the leaves taste better after a frost.
Three heritage varieties of kale
'Ragged Jack' has purple-veined, grey-green leaves, but seems very similar to the more widely-available 'Russian Red' (from Marshalls and Chiltern Seeds). The other is 'Hungry Gap', a well-named Russian variety. The divided leaves are late enough to follow winter brassicas and precede purple sprouting - so it definitely does fill the gap.