Brassica
How to grow kale
Brassica oleracea (Acephala group)
Kale is the easiest brassica to grow and the hardiest, cropping from September to April when little else is fresh. Sow in modules in April or May, plant out in June or July 45 cm apart in firm soil, and net against pigeons. It stands poorer soil, light shade and hard frost better than cabbage. Pick the lower leaves a few at a time and the plant keeps growing from the top, finishing with tender flowering shoots in spring.
- Hardiness
- Fully hardy, the toughest brassica
- Position
- Full sun to light shade
- Soil
- Fertile, firm
- Ideal pH
- 6.5 to 7.5
- Water
- Moderate
- Feeding
- Heavy feeder
Sowing and planting kale
WhenSow Mar to Jun; transplant Jun to Jul; harvest Sep to Apr
Starting off
Sow 1 to 2 cm deep in modules or a seedbed at 10 to 20 °C from March to June, germinating in 7 to 10 days; a May sowing gives the best winter crop. Transplant in June to July at 6 to 8 weeks with 5 leaves. For baby leaves sow direct in drills every 3 weeks from April to September.
Spacing and planting
Plant 45 cm apart in rows 45 to 60 cm apart for full-size plants, or 15 cm each way for baby leaves. Plant deep to the first leaves and firm hard. Compact types such as 'Dwarf Green Curled' and 'Nero di Toscana' crop happily in a 30 cm pot through winter.
Varieties worth growing
- Nero di Toscana
- Cavolo nero: long, dark, blistered leaves with the best flavour for cooking. Upright and narrow, so it fits a small bed.
- Reflex F1
- Tightly curled, blue-green leaves on a sturdy plant that stays clean and upright through hard winters without yellowing.
- Redbor F1
- Deep purple curly kale that colours more strongly after frost. As hardy as the green types and good enough for a flower border.
- Red Russian
- Flat, grey-green, frilled leaves with purple veins, more tender than curly kale. The best one for baby salad leaves.
- Pentland Brig
- Gives three crops: leaves in winter, then leafy side shoots, then broccoli-like flowering spears in March and April.
Kale month by month
Timings are for central England. Allow two weeks later in the north and on cold, heavy soil.
- January
Pick lower leaves as needed. Check nets.
- February
Keep picking. Top-dress with nitrogen at the end of the month.
- March
Pick leafy side shoots. First sowing in modules under cover.
- April
Pick flowering shoots before the buds open, then clear the old plants. Sow in modules. Sow baby leaf direct.
- May
Main sowing for winter. Keep seedlings under fleece against flea beetle.
- June
Transplant 45 cm apart, deep and firm, and water in. Mesh on.
- July
Finish transplanting. Water new plants until established.
- August
Check for caterpillars. One nitrogen top-dress. Water in drought.
- September
Begin picking lower leaves. Last sowing of baby leaf. No more feed.
- October
Earth up stems and stake tall plants. Swap insect mesh for pigeon netting.
- November
Pick. Remove yellowing leaves from the base.
- December
Pick. Leaves are sweeter after frost.
Feeding kale
Hungry, but less demanding than cabbage or sprouts. A base dressing at planting, one nitrogen top-dress in August, nothing through autumn and winter, then a second top-dress in late February for the spring shoots.
Hungry but the most forgiving brassica, a balanced feed keeps the leaves coming.
Feeding plan
A week before transplanting, June or July
Fruit & Vegetable Fertiliser 4-5-6
70 to 100 g/m² raked in and the bed trodden firm: 14 to 20 g per plant at 45 by 45 cm (0.2 m² each). Use the lower figure after a legume crop.
August
Organic Nitrogen Fertiliser 13% N
25 to 40 g/m², once: 5 to 8 g per plant (25 to 40 x 0.2), scattered round the stem and watered in.
September to January
Nothing
Soft autumn growth is the first to rot and be frosted.
Late February to early March
Organic Nitrogen Fertiliser 13% N
25 g/m², about 5 g per plant, to replace what winter rain has leached and drive the spring shoots.
Pots, at planting and again in August
Fruit & Vegetable Fertiliser 4-5-6
5 g per litre of compost at planting: 75 g for a 30 cm pot of about 15 litres. Then 2 g per litre as a top-dress in August: 30 g.
Signs to watch
Lower leaves yellow and plants stall in spring
Nitrogen short after winter leaching
Nitrogen top-dress in February to March
Purplish tints and slow growth on cold, wet ground
Phosphorus locked up by cold, not short
Mulch and wait
Soft, floppy leaves rotting at the base
Autumn excess nitrogen
Stop feeding by September and firm the soil
Pests, diseases and problems
Clouds of tiny white flies under the leaves, which become sticky and sooty
Cabbage whitefly, kale's most common pest, present all year
It rarely reduces the crop. Pick off and compost the worst lower leaves, wash picked leaves in a bowl of water, and plant under insect mesh to keep numbers down from the start.
Leaves torn to the ribs in winter, especially in snow
Wood pigeons
Net on a frame tall enough to clear the plants from October to April; pigeons land on netting draped over the leaves and feed through it.
Holes in leaves and caterpillars along the midribs, July to October
Cabbage white butterfly caterpillars
Fine netting or mesh from planting. On open plants, rub off eggs and pick caterpillars off twice a week.
Grey, waxy aphid colonies deep in the curled leaves
Mealy cabbage aphid
Squash early colonies or blast them out with a hose. Remove and compost old stumps by April.
Tall plants lean or rock loose at the base after autumn gales
Wind rock, which tears the roots
Plant deep and firm, draw soil up round the stems in October and stake tall varieties on exposed plots.
Plants stunted and wilting on warm days, roots swollen and knobbly
Clubroot. Kale suffers less than cabbage or sprouts but is not immune
Lime acid soil to pH 7, improve drainage, and raise plants in 9 cm pots so they go out with a good root system.
Harvest and rotation
Harvest and storage
Pick young leaves from the bottom of the stem up from September, 12 to 16 weeks from sowing, leaving the crown to keep growing; take no more than a third of the plant at once. Spring side shoots in March to April are the sweetest. A plant gives 1 to 1.5 kg over winter. Use within 3 days from the fridge or blanch and freeze.
Rotation and companions
Rotation: brassica group, 4-year gap, after peas or beans on limed ground. Beetroot and chard alongside share the space without competing.
Good to knowVery hardy; pick from the bottom up and it crops right through winter.
Growing kale in pots
Kale is the best brassica for a pot. One plant of Nero di Toscana or a dwarf curly variety fills a 30 cm pot (about 15 litres) and crops from autumn to spring. Use loam-based or good peat-free compost, plant deep and firm it well. Water regularly through summer; from November rain usually does the job. Stand the pot out of the wind, since a top-heavy plant in a light pot blows over. For baby leaves, sow Red Russian thinly in a trough and cut at 10 cm.
Kale: common questions
When should I sow kale in the UK?
Sow from March to June, with late April to May the best time for a winter crop. Start seed in modules, 1 to 2 cm deep, and plant out six to eight weeks later in June or July. For baby salad leaves, sow direct every three weeks from April to September.
How do you pick kale so it keeps growing?
Take the lower leaves first, snapping them down and off the stem, and leave the top rosette of eight or so young leaves to keep growing. Never take more than a third of the plant at once. In spring, pick the side shoots at 10 to 15 cm before the flowers open.
Does kale survive frost?
Yes. Kale is fully hardy and stands through a normal British winter without protection, and frost improves the flavour by turning starch in the leaves to sugar. The danger in winter is pigeons, so keep the netting on.
Sources
Growing information on this page was checked against these references in November 2026. Feeding rates are Dr Forest label rates.