How to grow cabbage

Make a raised nursery bed or use trays with clean, fresh media — never soil from an old cabbage patch, which carries damping-off and clubroot.

Sow the seed about 1 cm deep — just cover it, about one fingertip deep. Space seeds 2–3 cm apart, or in rows a hand-width (≈10 cm) apart.

Keep the bed warm, around 25–30 °C, and lightly moist to sprout — seedlings usually show in 5–10 days.

Water in the morning and only enough to stay damp, not soggy — too much water gives leggy seedlings and damping-off (seedlings collapse at the soil line).

When seedlings crowd, prick out (thin) the weakest so the rest grow stocky, with room and light.

Your seedlings are ready to transplant at 4–6 true leaves, stem about pencil-thick, roughly 4–6 weeks old.

If seedlings go thin and leggy → give them more sun and less water, and thin the crowded ones so each has room to firm up.

Starting about 7 days before transplant, give the seedlings more sun each day and move them into open conditions.

Cut back the watering — let them feel a little dry between waterings so their stems toughen (but never wilt to the point of drooping badly).

Stop feeding during this week — you want tough, not lush, seedlings.

You will see the leaves go a little tougher and bluer-green — that is the seedling toughening up.

Water the nursery well the evening before you lift, so the seedlings go into the field full of moisture and lift with soil on their roots.

If a seedling wilts badly during hardening → ease back: the aim is tough, not starved. Give a little water and harden more gently.

Only lime if a soil test — or past crops that stayed yellow, stunted or wilted even with fertiliser — says your soil is sour. Your recommendation gives the amount for your field.

For cabbage, aim a little sweeter than usual (toward pH 7.2) where clubroot is known, not just to the normal growing range — the extra sweetness is what holds clubroot back.

Spread it evenly over the whole bed, like sprinkling flour by hand — patches give patchy results and leave sour spots where clubroot hides.

Work it into the topsoil with a hoe. Lime only helps the soil it is mixed into; left on top it does almost nothing.

Do it 2–3 months before transplanting (a good time is right after clearing the last crop) — lime is slow, so late liming won't help this season.

Do the bed work about 1–2 weeks before you transplant — dug, manured and fertilised — so the soil settles before the seedlings come out of the nursery.

Choose a bed on land that has not grown any cabbage-family crop for at least 3 years, and that drains well.

Dig and loosen the soil deeply and break the clods to a crumbly tilth, so the shallow roots spread easily and water soaks in.

Work in well-rotted manure or compost — dark, crumbly, no strong smell — about a wheelbarrow every few strides. Fresh, strawy manure burns roots and brings weed seeds.

Apply the basal fertiliser your recommendation gives — cabbage needs a compound high in potash (potassium), not just nitrogen, to build firm heads.

On heavy or wet soil, make raised beds or ridges so water never stands around the stems.

Level the surface so watering is even, and keep basal fertiliser out of the exact spots where seedling stems will sit.

Buy stocky, dark-green seedlings with 4–6 true leaves and a stem about pencil-thick — not tall, thin, pale or pot-bound (roots coiled tight in the tray).

Check each one: no yellow V-shaped patches with black veins (black rot), no aphid colonies in the heart, and no wilting. Reject the whole batch if many look sick.

Buy from a nursery that raises seedlings on clean, fresh media, well away from any old cabbage-family patch — that's how black rot and clubroot travel.

Transplant them within a day or two of buying, and keep them shaded and watered until you do.

Transplant in the cool of the day — a cloudy day, or late afternoon/evening — never in the hot midday sun.

Water the nursery first so seedlings lift with a ball of soil on the roots; disturb the roots as little as you can.

Make a hole at the recommended spacing — about 65 cm between rows (roughly three hand-spans) and 40 cm between plants (two hand-spans).

Set each seedling to the same depth it grew in the nursery — firm soil around the roots, but never bury the growing point (the little heart in the centre).

Water in at once — a cupful or two at the base of each plant — so the soil settles snugly around the roots with no air pockets.

If a seedling wilts flat and doesn't recover by the next morning → replace it from your spares while there is still time to catch up (keep a few spare seedlings in the nursery for this).

Keep the topsoil steadily moist — not waterlogged — while the seedlings root; water every 2–3 days, more often in heat or on sandy soil that dries fast.

Water gently at the base of the plants, in the cool of the day.

Check by pushing a finger in: water when the top few centimetres feel dry.

Replace any dead or failed seedlings within the first week or two, from your spares, so the replacements can still catch up with the rest.

If gaps are left unfilled → the crop matures unevenly: fill them early, while spares are still the same age as the field.

Once the soil is moist and the seedlings are in, spread dry grass, straw or leaves between the plants.

Lay it about a hand-thick so it shades the soil and holds the damp.

Keep the mulch a hand's width off the stems — mulch piled against the stem stays wet and rots it, and hides slugs.

Top up the mulch as it rots down through the season.

Every 3–4 days, walk a large "W" across the field so you cover all corners and the middle, not just the edge by the path.

Cutworms: look for seedlings cut clean off at soil level (worst in the morning). Scratch the soil around the stump to find the fat, grey, curled caterpillar and squash it.

Check for wilting or checked transplants that are struggling to root, and count the gaps where seedlings have died.

Turn a few leaves over and look for early flea-beetle shot-holes (tiny round holes) and grey-green aphid colonies.

If cutworms are cutting plants → act now: hand-pick at night, put a cardboard or tin collar around stems, or use a recommended bait, and replace the cut seedlings from your spares.

Apply when the plants have taken and are growing away — new leaves opening, about 4 weeks after transplant.

Band about half the nitrogen (ammonium nitrate, sold as 'AN', or urea) a hand's width to the side of the plants, not on top of them.

Do it on moist soil (after a weeding or light rain) and water it in or cover it, so it doesn't gas off and go to waste.

Keep the fertiliser out of the heart and off wet leaves — grains lodged in the heart or stuck to wet leaves scorch them.

Remember cabbage needs as much potash as nitrogen — make sure your programme keeps potassium going in, not just N.

Wash your hands afterwards and keep fertiliser away from food and water.

If the lower leaves are pale and the plant is small → it is hungry: don't skip or delay this feed.

Weed by about 2–3 weeks after transplant, before the weeds get bigger than the cabbage.

Hoe shallowly between and within the rows — the roots are just under the surface.

Close to the plants, pull the weeds by hand rather than hoeing deep against the stems.

Time this weeding just before you top-dress, so the nitrogen feeds the cabbage and not a fresh flush of weeds.

In dry areas, leave the pulled weeds lying between the rows as a mulch to hold moisture.

Water every 5–7 days — more often in heat or on sandy soil — to keep the soil evenly moist to a spade's depth.

Aim for steady, not feast-or-famine — big swings between bone-dry and flooded are what cause trouble later.

Check with a finger: water when the top few centimetres are dry, before the plants wilt.

Don't waterlog — cabbage roots rot and clubroot spreads in standing water. Drain low spots.

If the crop has dried out and wilted → bring the water back gently over a day or two, not in one flood, or you shock the plants.

Walk the crop weekly in a "W", turning leaves over and looking into the open heart where pests hide.

Diamondback moth: small green caterpillars and "window-pane" grazing — thin, papery patches where only the underside skin of the leaf is left. Disturbed, the caterpillars wriggle and drop on a thread.

Cabbage aphids: grey-green, waxy colonies packed on the growing point and leaf undersides.

Black rot: yellow, V-shaped patches running in from the leaf edge, with black veins inside the V. Worst in warm, wet weather.

Leaf miners: pale, wiggly tunnels traced inside the leaf.

Threshold: when about 2 plants in every 10 show fresh caterpillar damage, spray Bt (a caterpillar-only spray) or a registered product, covering the leaf undersides, and switch to a different chemical group each spray (the group is marked on the label as a number — ask your agro-dealer which group a product is in, and rotate to a different one each time).

Spray safely: cover your skin, eyes and nose, spray in the cool of the day with the wind behind you, keep spray off food, and wash afterwards. Never spray closer to harvest than the product's pre-harvest interval — the number of days you must wait between the last spray and cutting the heads (printed on the label; ask your agro-dealer if you're unsure), because you eat this crop.

If you find black rot → remove the worst plants, stop working the rows while the leaves are wet, and water at the base (not over the top) to slow its spread.

Apply as the youngest leaves start to fold inward and cup like a loose bowl — around 7–8 weeks after transplant.

Band the last nitrogen split to the side of the plants, on moist soil, and water it in.

Keep potash high into the head — it is what makes the head firm, heavy and good to store.

If hollow or brown stem (boron shortage) is a known problem in your area, apply the small amount of boron your recommendation gives, spread very evenly — too much boron harms the crop, so never guess the dose.

This is the last nitrogen of the season — more N after this gives soft, loose heads that split and rot in storage.

Keep fertiliser off the head and out of the heart, and wash your hands afterwards.

If you're unsure whether to add more nitrogen late → don't: steady potash and steady water do more for the head now than extra N.

Keep the soil constantly moist through cupping and heading — water every 3–5 days, more often in heat.

Never let the crop wilt at this stage, even for a day.

Water at the base, early or late in the day — soaking the heads late keeps them wet overnight and invites disease.

Above all, keep it even — no bone-dry spells followed by floods.

If the crop has been left dry → bring the water back gradually over a day or two, never in one heavy soak, or the sudden swell causes tip-burn and splitting.

Walk the crop weekly, gently opening the cupping leaves to check inside the heart, where the caterpillars now feed.

Diamondback moth: green caterpillars and window-pane grazing, now down in the folding leaves and heart.

Cabbage aphids: grey-green colonies tucked inside the cupping leaves.

Downy mildew: yellow patches on the upper leaf with a grey-purple fuzz underneath, worse in cool, damp weather.

Clubroot: plants that wilt in the day and recover at night — lift one and check the roots; swollen, clubbed roots mean clubroot.

Tip-burn: browning inner-leaf edges — this is water/calcium, not a pest; fix it by steadying the moisture.

Bolting: a plant stretching upward to throw a flower stalk instead of heading — usually from a cold spell; note it but it can't be reversed.

Threshold + safe spraying: at about 2 plants in 10 with fresh caterpillar damage, spray Bt or a registered product into the heart and under the leaves, switch to a different chemical group each time (ask your agro-dealer which group each product is in, and rotate to a new one), cover skin/eyes/nose, spray in the cool with the wind behind you, and never spray inside the product's pre-harvest interval — the days you must wait between the last spray and cutting the head (on the label, or ask your agro-dealer).

If you find clubroot → lift and burn the affected plants, don't plant any cabbage-family crop there again for years, and lime that ground.

Keep water steady and even right to harvest — water every 3–5 days, adjusting for heat.

Never give a sudden heavy soak after a dry spell — that is what bursts a firm head.

Once heads are firm, you can ease the water back a little to slow splitting while you cut in passes.

If you must taper off before harvest, do it gradually, not all at once.

If firm heads are at risk of splitting (after rain, or a firm head you can't cut yet) → hold the water back a little and harvest those heads first.

From about day 80 after transplant, squeeze a few heads across the field with your open palm.

Firm and solid all the way through → ready to cut (this is your signal to start harvesting).

Still soft, loose or spongy → not ready: give it more time.

Note which heads are firmest — those get cut first.

Look on top for the first fine cracks, the sign a head is about to split.

If a head is still soft → leave it, keep the water steady, and squeeze again in a few days. If it is firm and starting to crack → cut it now, before it splits.

Walk the crop weekly, checking the tops and the outer wrapper leaves of the heads.

Splitting: look for fine cracks on top of firm heads — cut these at once.

Aphids in the head: grey-green colonies trapped in the wrapper leaves and outer head, hard to remove before market.

Soft rot: soft, slimy, foul-smelling wet patches on the head — a bacterial rot that spreads fast in warm, wet weather.

Lift out and remove any rotting heads from the field — don't leave them to infect the rest.

If soft rot is spreading → cut out the affected heads, improve drainage, and don't cut or handle heads while they are wet, which spreads the rot.

Check the head is firm and solid to a gentle squeeze and at market size before you cut it.

Cut the stem just below the head with a sharp knife.

Leave a few wrapper leaves on the head — they protect it from bruising and drying on the way to market.

Cut in the cool of the day (early morning is best) and keep cut heads out of the sun.

Work in passes every 5–7 days, taking the firmest, most mature heads each time.

If you have sprayed recently, make sure the product's pre-harvest interval — the number of days to wait between the last spray and cutting — has fully passed before you cut heads to eat or sell (the days are printed on the label; ask your agro-dealer if you're unsure).

If a head isn't firm yet → leave it and come back in a few days; if it is firm and cracking → cut it now, before it splits.

Trim the loose and damaged outer leaves, leaving a few clean wrapper leaves for protection.

Grade by size and firmness so each bag or crate holds uniform heads — buyers pay more for an even pack.

Handle gently — don't drop or throw heads; every bruise becomes a rot spot.

Get the heads out of the sun quickly and keep them cool and humid (near 0–4 °C for firm storage types; early types should go to market fast).

Stack so air can move between heads — don't seal warm, damp heads in a tight bag, or they heat and rot.

If a head is soft, split or damaged → sell or eat it first and keep it out of the packed, sound heads, so it doesn't rot the rest.