Brassica
How to grow purple sprouting broccoli
Brassica oleracea (Italica group)
Purple sprouting broccoli is the overwintering broccoli. Unlike summer calabrese, which makes one green head in three months, it is sown from April to June, planted out in June or July, stands through winter and crops from January to May, when the garden has little else. It needs a winter's cold to trigger the spears, so there is no hurrying it. Success comes down to firm planting, staking, and keeping pigeons off for nine months.
- Hardiness
- Fully hardy, overwinters outside
- Position
- Full sun
- Soil
- Firm, rich, moisture-retentive
- Ideal pH
- 6.5 to 7.5
- Water
- Moderate, water well at transplanting and in a dry summer
- Feeding
- Heavy feeder
Sowing and planting purple sprouting broccoli
WhenSow Apr to Jun; transplant Jun to Jul; harvest Jan to May
Starting off
Sow 1 to 2 cm deep in modules or a seedbed outdoors in April to June, germinating in 7 to 12 days at 10 to 20 °C; sow early varieties such as 'Rudolph' in April for January spears and late ones in June for April. Transplant in June to July at 6 to 8 weeks with 5 true leaves, watering the hole first.
Spacing and planting
Plant 60 cm apart in rows 75 cm apart; the plants reach 90 cm tall and wide by winter. Plant deep to the first leaves, firm very hard and stake with a 1.2 m cane on exposed sites. Not a container plant.
Varieties worth growing
- Rudolph
- The earliest traditional variety: from an April sowing it can be cut from December or January in a mild winter.
- Red Arrow
- Heavy cropper for February and March with plenty of side spears; the dependable main-season choice.
- Claret F1
- Late and vigorous, cropping in April and into May with thick, uniform spears. Grow with an early variety to cover four months.
- White Eye
- A white sprouting broccoli with creamy, cauliflower-like spears in March; milder than the purple forms.
- Santee F1
- Needs no winter cold. Sown in spring it crops the same year from late summer into autumn, which suits gardens too exposed to overwinter tall plants.
Month by month
Timings are for central England. Allow two weeks later in the north and on cold, heavy soil.
- January
First spears from Rudolph in a mild winter. Check stakes and netting.
- February
Nitrogen top-dress as the spears start to form. Cut the central spear first.
- March
Main harvest. Cut side spears every 2 to 3 days so the plant keeps producing.
- April
Harvest late varieties. Sow early varieties in modules or a seedbed.
- May
Last spears. Pull up and compost the stumps as soon as cropping ends. Sow main varieties.
- June
Sow late varieties. Transplant April sowings deep into firm ground, with collars.
- July
Finish transplanting. Water in well. Mesh against butterflies.
- August
Water in dry spells. Light balanced top-dress mid month. Check for caterpillars.
- September
Earth up the stems and stake every plant. No more feeding until February.
- October
Replace insect mesh with pigeon netting. Remove yellow leaves.
- November
Check stakes and ties after every gale.
- December
Knock snow off the netting. Rudolph may give its first spears.
Feeding purple sprouting broccoli
In the ground for up to eleven months, so it is fed in three small stages, not one large one: at planting, in late summer, and in February as the spears form. Nothing between September and February, when soft growth would not survive the winter.
Long in the ground (sown spring, cropped late winter to spring), feed steadily and topdress in late winter.
Feeding plan
The winter before planting, only if a test shows pH below 6.5
Garden Lime (calcium carbonate)
About 0.5 kg/m², at least a month apart from any manure.
June or July, a week before transplanting
Fruit & Vegetable Fertiliser 4-5-6
70 g/m² raked in. At 60 by 75 cm each plant has 0.45 m², so about 32 g per plant.
Mid August, once
Fruit & Vegetable Fertiliser 4-5-6
50 g/m², about 22 g per plant, hoed in lightly and watered. This is the low end of the label top-dress rate; the label times it for May to June, but this crop is not planted until then. The season total is 120 g/m², under the 150 g/m² limit.
February, as the first spears form
Organic Nitrogen Fertiliser 13% N
40 g/m², about 18 g per plant or half a rounded handful, scattered round each plant. Winter rain will have washed most of the available nitrogen out of the soil.
Before planting, only where earlier brassicas had hollow, brown-centred stems
1 to 2 g/m², a quarter to half a level teaspoon per square metre, scattered evenly, once a season and never exceeded.
Signs to watch
Hollow stems with brown centres
Boron short on limed, light ground
Seaweed feed or a light borax dressing
Pale lower leaves and few spears in February
Nitrogen short after winter leaching
Nitrogen top-dress as spears form
Lax, soft growth that rocks in wind
Autumn nitrogen and loose planting
Firm, stake and stop feeding by September
Pests, diseases and problems
Leaves stripped to the ribs and growing tips pecked out between November and March
Woodpigeons. On this crop they are the main cause of failure, because it stands all winter when they are hungriest
Net on a frame at least 1.2 m high from October until the last spear is cut, pegged down at the edges.
Newly planted transplants wilt and collapse in June and July; roots eaten
Cabbage root fly
Collars round each stem at planting, or fine mesh over the bed.
Leaves holed and fouled with droppings in late summer
Cabbage white caterpillars, at their peak just after this crop goes out
Fine insect mesh on tall hoops from planting until October, then change it for pigeon netting.
Plants lean, rock loose and snap at the base after gales or snow
Top-heavy plants in loose or wet soil
Plant deep and firm, draw soil 10 cm up the stem in September and tie each plant to a 1.2 m stake. Knock snow off the netting.
White insects fly up from the leaves in clouds in autumn and winter
Cabbage whitefly, which overwinters on standing brassicas
Tolerate it; the spears are not affected. Strip yellowing lower leaves, and clear the plants promptly in May so the pest cannot move to new brassicas.
Stunted plants that wilt in sun, with swollen, knobbly roots
Clubroot
Lime to pH 7 or a little above, drain the ground, and raise plants in 12 cm pots so they go out with a large healthy root system.
Harvest and rotation
Harvest and storage
Cut the central spear first when 10 to 15 cm long with tight purple buds, 36 to 44 weeks from sowing, then side spears every 2 to 3 days for 6 to 8 weeks; cut above a pair of leaves and never strip the plant bare. A plant yields 500 g to 1 kg. Eat within 2 days or blanch and freeze; it does not store.
Rotation and companions
Rotation: brassica group, 4-year gap, following early peas or broad beans on limed ground. Interplant young transplants with lettuce or spinach in July to use the space before they bulk up.
Good to knowStake the tall plants on windy sites; the cold of winter is what triggers spear production.
Growing in pots
Not a container plant. Purple sprouting broccoli grows 90 cm tall and as wide, stands outdoors for nine months or more and has to hold itself upright through winter gales, which it can only do rooted deep in firm ground. In a pot it blows over, dries out in summer and freezes at the root in winter. If you have no open soil, the nearest thing that works in a container is a spring-sown, same-year variety such as Santee F1, one plant to a 40 litre tub, staked, though the yield is modest for the space and the watering it takes.
Common questions
What is the difference between broccoli and purple sprouting broccoli?
Broccoli, properly called calabrese, makes one large green head in summer or autumn about three months after sowing. Purple sprouting broccoli is a hardy overwintering plant that produces many small purple spears from January to May, eight to ten months after sowing. They are grown at different times and are not interchangeable.
Why has my purple sprouting broccoli not produced any spears?
Most often it simply is not time yet. Traditional varieties need several weeks of winter cold before they form spears, and late ones such as Claret do not crop until April. Plants sown after June, or badly grazed by pigeons, may be too small to crop well.
How do you harvest purple sprouting broccoli so it keeps cropping?
Cut the central spear first, then the side spears every two or three days while the buds are tight. Cut each spear with 10 cm of stem, just above a pair of leaves, and more will grow from below the cut. Once the buds open into yellow flowers the plant stops producing.
Sources
Growing information on this page was checked against these references in November 2026. Feeding rates are Dr Forest label rates.