Growing brassicas: cabbage, kale, broccoli & sprouts
The cabbage family is the workhorse of the winter garden — the crops that keep the kitchen going when everything else has packed up. Get a few right and you'll be picking kale in the snow, cutting sprouting broccoli in the hungry gap, and pulling sprouts for Christmas dinner you grew yourself. They ask for two things in return: firm ground, and protection from everything that wants to eat them first.
This is the family overview — for the full sowing dates and varieties of each crop, follow the links through to its own page.
One family, a year-round harvest
Brassicas are one big, generous family. The most familiar of them — cabbage, kale, broccoli, cauliflower, sprouts and kohlrabi — are, astonishingly, all the same plant bred into different shapes, with swede, turnip and the oriental leaves as close cousins. Because they share the same pests and diseases, we grow them together and rotate them around the beds as a group. Between them they crop in every season, so a few well-chosen types keep you in greens all year.
The easiest and hardiest of the lot — sow in late spring/summer for leaves that stand right through winter. Forgiving of poor soil and cold.
Summer, autumn, winter and spring types between them give cabbages almost year-round. Sow spring cabbage in late summer for early next year.
Sow in early summer for spears next spring, in the hungry gap. A long wait, but the most welcome harvest of the year.
The fussiest brassica — needs rich, firm soil and steady moisture or the curds 'button' small. Worth it when it works.
Sow in spring for Christmas sprouts. Plant deep and firm — loose soil gives 'blown', open sprouts.
Sow in a seedbed, plant firm
Most brassicas are best raised in a seedbed or in modules and transplanted, rather than sown where they're to grow — it saves space while the slower spring and summer crops finish, and gives you sturdy young plants to set out. Sow thinly, grow them on until they're a few inches tall with a good root, then move them to their final spacing.
The golden rule is firmness. Brassicas hate loose ground: plant them deep, right up to the lowest leaves, and firm the soil hard around the stem — with your knuckles, or even your heel for the big ones. Loose roots are behind most brassica disappointments: wind-rocked cauliflowers, blown sprouts that won't tighten, plants that simply sulk. Water them in well, and keep them watered as they establish.
Everything wants to eat them — here's the defence
It's worth knowing from the start: a brassica bed needs protecting, or the cabbage whites and pigeons will have it before you do — we've learned that one the hard way. The good news is that the defences are simple and last for years.
- Butterfly netting— the headline act. Fine mesh held off the leaves stops cabbage whites laying their eggs at all. The single most effective thing you can do. On Amazon →
- Check for eggs & caterpillars— if anything gets under the net, turn the leaves and rub off the clusters of yellow eggs before they hatch.
- Brassica collars— little discs around the stem base stop cabbage root fly laying at the roots. Easy to make from cardboard or carpet underlay.
- Pigeon protection— pigeons strip winter brassicas to the stalks. The same netting, kept taut, keeps them off too.
- Companion planting— aromatic herbs and onions help confuse the pests. See companion plants for brassicas for the supporting cast — though netting is still the headliner.
Common questions
What vegetables are brassicas?
The cabbage family: cabbage, kale, broccoli and calabrese, cauliflower, Brussels sprouts, kohlrabi, swede, turnips and oriental leaves like pak choi and mustard. They share pests and diseases, so grow and rotate them as a group.
How do I protect brassicas from cabbage white butterflies?
Fine butterfly netting held off the leaves is by far the most reliable defence — it stops the butterflies laying at all. Back it up by checking leaf undersides for yellow eggs and rubbing them off, and by growing aromatic companions to confuse the pests.
Why do my brassicas fall over or grow loosely?
They need firm soil and deep, firm planting. Plant up to the first leaves, heel them in hard, and stake tall ones like sprouts and sprouting broccoli. Loose roots give wind-rock, blown sprouts and small curds.
What is clubroot and how do I prevent it?
A soil disease that swells and distorts brassica roots and lingers for years. It thrives in acidic, wet soil, so lime to raise the pH, improve drainage, rotate brassicas, and raise your own plants in clean compost to avoid importing it.