Cabbage has a reputation for being easy, and then a reputation for being disappointing — a lot of gardeners sow a packet, grow handsome leafy plants all summer, and never get a single solid head. Almost every one of those failures comes down to one misunderstanding: cabbage is not one crop with one sowing date. It is four crops, sown at four different times, and the variety on the packet decides which slot it belongs in.
Brassica oleracea var. capitata is a coastal cliff plant that humans bred into a storage organ. Get its three demands right — firm ground, steady water and enough space to shade its own growing point — and it hearts up reliably. This guide covers the four sowing seasons, module-raising, spacing that lets you choose the size of your heads, clubroot, cabbage whites, and the second harvest most people throw on the compost heap.
- Botanical name Brassica oleracea var. capitata — spring, summer, autumn and winter types
- Sow spring cabbage mid Jul–Aug · summer Feb–Apr · autumn & winter Apr–May
- Germination 7–12 days at 12–20 °C — modules beat a seed bed every time
- Spacing 30–50 cm — the spacing you choose sets the size of the head
One vegetable, four sowing seasons
Read the packet before you read the calendar. Cabbage varieties are bred for a specific slot, and sowing the right seed at the wrong time is the single commonest cause of a plant that never hearts.
Spring cabbage is sown mid-July to late August, planted out in September or early October, and cut the following April to June — filling the hungry gap when almost nothing else is ready. Summer cabbage is sown February to April, often started indoors, for July and August heads. Autumn cabbage goes in April to May for September and October. Winter cabbage and savoy are also sown April to May but stand in the ground through frost, which is a feature rather than a compromise: cold converts starch to sugars, so a savoy cut after a hard frost is noticeably sweeter than the same plant in October.
If you are reading this at the end of August, spring cabbage is the sowing that still makes sense — just. Mid-July to mid-August is ideal; a late-August sowing works in mild gardens if you raise it fast in modules and get it planted by the end of September. Aim for plants that go into winter small. A spring cabbage that puts on a thick stem before the cold arrives reads the winter as a completed year and bolts to flower in April instead of hearting — the same vernalisation trigger that makes overwintered onions run to seed.
Sowing cabbage: modules beat a seed bed
Brassicas transplant willingly — unlike carrots or parsnips, they barely notice being moved — which makes module-raising the obvious route. Sow two seeds per cell about 1.5 cm deep in ordinary multipurpose compost, water, and keep them at 12–20 °C. Germination takes 7–12 days. Thin to the strongest seedling as soon as the first true leaf shows.
Keep the modules outside or in an unheated frame, not on a warm windowsill. Cabbage seedlings raised too warm and too dim stretch within a week, and a leggy brassica seedling never really recovers. Plant out at four or five true leaves, roughly five weeks from sowing. If nothing comes up at all, the usual suspects are dry compost or old seed — worth a quick germination check.
From seed to planted-out, step by step
- Sow into modules, not open ground Two seeds per cell, 1.5 cm deep, thinned to one. Modules dodge slugs, flea beetle and pigeons during the weeks when a seedling cannot afford to lose a leaf.
- Grow them on cool and bright Outdoors or in a cold frame. Short, stocky, blue-green plants transplant far better than tall pale ones.
- Firm the ground — really firm it Brassicas want settled, consolidated soil. Walk the bed heel-to-toe before planting. Fluffy, freshly dug ground gives loose, leafy plants that never heart. Do any soil improvement weeks in advance, not on the day.
- Plant deep and water into the hole Set the plant with its lowest leaves just above soil level, firm with your knuckles, then fill the planting hole with water rather than sprinkling the surface.
- Net before you think you need to 7 mm mesh over hoops goes on the day you plant. Once cabbage white eggs are on the undersides of the leaves you are picking caterpillars, not preventing them.
- Water steadily, feed once A deep soak weekly beats a daily splash. One nitrogen-rich feed as the plants start to fill their space is plenty; spring cabbage gets its feed in March, not autumn.
Spring cabbage — sow now
Pointed and loose-headed types such as Duncan, Wheeler's Imperial and Greyhound.
- Sow mid-Jul to late Aug, plant out Sept–early Oct at 30 cm
- Overwinters small; feed in March, cut April–June
- Thin every other plant in spring and eat them as spring greens
Winter cabbage & savoy — sow in spring
Dense ballheads, red cabbage and crinkled savoys built to stand in frost.
- Sow Apr–May, plant out Jun–Jul at 45–50 cm
- Stands outside all winter; frost improves the flavour
- Red and white ballheads store for months in a cool shed
Spacing decides the size of your cabbage
A cabbage hearts when it has grown enough outer leaves to shade its own growing point; the inner leaves then stay pale, stack up and firm into a head. That mechanism has a very practical consequence — spacing controls head size directly. Plant at 30 cm and you get tight 400–600 g heads that mature sooner and suit a small household. Plant at 45–50 cm and the same variety builds 1.5–2 kg heads that take several weeks longer.
Neither is more correct. If you would rather eat a cabbage a fortnight than wrestle a giant one into the fridge, sow a short row every three weeks and space it tight — the same logic behind succession sowing for salads.
Clubroot, caterpillars and pigeons
Cabbage has three real enemies and only one of them is dramatic.
Clubroot is the serious one: a soil-borne organism that swells the roots into useless galls and survives up to twenty years in infected ground. There is no spray. Raise the pH towards 7.0–7.5 with garden lime the autumn before, raise your plants in generous 9 cm pots so they go out with a strong root system, and never follow a brassica with a brassica — see our guide to crop rotation. The same rule applies to the whole family, including mustard greens and mustard sown as a green manure.
Cabbage white butterflies are beaten by timing, not by treatment. Fine 7 mm mesh over hoops, edges buried or weighted, keeps the butterflies off entirely; it must be on before they arrive, and it must not rest on the leaves, or eggs get laid straight through it. Wood pigeons do their damage in winter, stripping overwintering plants to the ribs, so leave the netting on until you harvest. For everything else that turns up, our guides to common garden pests and plant diseases cover the diagnosis. A few plants of companion planting around the bed will not replace mesh, but it does help the predators find the aphids.
Harvesting — and the second crop from the stump
Cut when the head feels solid under a squeeze. Use a knife and take the head off cleanly, leaving the stump and its outer leaves in the ground. Now cut a shallow cross about 1 cm deep into the cut face of that stump: on spring and summer cabbage it will push out four small secondary heads over the following six to ten weeks. It is the closest thing the vegetable garden has to a free lunch, and most gardeners pull the stump out instead.
Firm white and red ballheads keep for two to four months in a cool, airy shed — see harvesting and storing your produce for the conditions. Savoys and winter cabbage are best left standing and cut as needed; if a hard freeze is forecast and you want them a little more accessible, a fleece or cloche makes winter cutting a great deal more pleasant — more on that in our guide to extending the growing season.
Common mistakes
- Sowing the wrong type for the season. A summer variety sown in August will not produce a spring cabbage. Match the packet to the slot.
- Planting into loose, fluffy soil. Brassicas need firmed ground. If you can push a finger in easily, tread it first.
- Netting after the first caterpillar. Mesh is prevention. By the time you see holes, the eggs hatched days ago.
- Feeding spring cabbage in autumn. Soft, sappy growth going into winter is exactly what rots or bolts. Wait until March.
- Growing brassicas in the same bed every year. Clubroot is cumulative and permanent. Rotate on a three or four year cycle from the start.
Frequently asked questions
Is it too late to sow cabbage at the end of August?
For spring cabbage, you are at the back edge of the window but not past it in a mild garden. Sow into modules now, keep them growing hard, and plant out by the end of September. Small plants overwinter better than large ones, so a late sowing is less of a handicap than it sounds. For summer, autumn or winter types, wait for spring.
Why won't my cabbage form a head?
Three usual causes: too much space and not enough time for the plant to shade its own crown, soil that was too loose at planting, or a variety sown out of its season. Erratic watering is the fourth — cabbage that dries out and then floods tends to split rather than firm.
Do I really need to lime the soil?
Only if your soil is acidic. Cabbage is happiest between pH 6.5 and 7.5, and higher pH suppresses clubroot, so on acid ground lime the autumn before planting. Never lime and add manure at the same time — leave several months between them.
Can I grow cabbage in a container?
Yes, with a caveat: one plant per 20–25 litre pot, and it will need watering almost daily in summer. Pointed spring types and compact ballheads work best. Our container growing guide covers compost and feeding, and the smaller-leaved lettuces make good companions in the same bed.
Cabbage rewards preparation more than fuss: firm ground, the right variety for the slot, mesh on early and a knife rather than a tug at harvest. Start with a pointed spring cabbage now and a savoy next April, and you will be cutting heads for most of the year. Browse our white and red cabbage seeds, the wider kale, broccoli and cauliflower ranges, everything you can still sow in September, or dig deeper in our growing guides library and the full vegetable seed collection.
