How to Grow Sprouting Broccoli
Brassica oleracea var. italica
Sprouting broccoli is sown in spring, grows through summer, and overwinters to produce cut-and-come-again spears from late winter into spring — a lean-season crop when little else is available. Sow under cover in April, plant out firmly at 60 cm spacing, and net immediately against pigeons. Stake tall plants in autumn to prevent wind rock, which is the most common cause of poor cropping.
When to Start
Direct sow outdoors as soon as soil reaches 5°C — typically early to mid spring. Can also be started indoors 5 weeks earlier for a head start.
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Growth Stages
Approximate days from start
Care Essentials
- Apply a balanced granular fertiliser when planting out, then top-dress with a nitrogen-rich feed in late autumn to support the plant through winter. Avoid high-nitrogen feeds in spring as this encourages leafy growth over spear production.
- Sprouting broccoli is sown in spring and overwinters as a large plant, producing cut-and-come-again spears from late winter into spring. Firm planting and staking prevent wind rock, which is the most common cause of poor cropping.
Growing Conditions
- Min. soil temperature
- 5°C+
- Germination temperature
- 15–25°C
- Sow indoors
- —
- Transplant out
- —
- First harvest
- —
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Spacing & Planting
| Plant spacing | 60 cm |
| Row spacing | 60 cm |
| Sow depth | 1 cm |
| Mature height | 90 cm |
| Mature spread | 60 cm |
Pests & Diseases
Pest Cabbage White Caterpillar
Identification: Pale yellow-green or yellow-and-black caterpillars on leaves; large irregular holes and dark frass pellets on foliage.
- Pick caterpillars off by hand and drop into soapy water.
- Apply Bacillus thuringiensis (Bt) spray to affected leaves — harmless to other wildlife.
- Spray with a pyrethrin-based insecticide in the evening to minimise impact on pollinators.
Pest Mealy Cabbage Aphid
Identification: Dense grey-white colonies on leaf undersides and growing tips; leaves curl and turn yellow; plants become stunted.
- Blast off colonies with a strong jet of water.
- Spray with insecticidal soap or dilute neem oil, covering all leaf undersides thoroughly.
- Apply a systemic aphicide containing thiacloprid or acetamiprid as a drench or spray.
Pest Cabbage Root Fly
Identification: Plants wilt suddenly despite moist soil; white maggots visible in roots when plant is lifted; collar of soil around stem may show fly activity.
- Fit brassica collars (10–15 cm discs) around each stem at planting to prevent egg-laying near roots.
- Apply parasitic nematodes (Steinernema feltiae) to the root zone.
- No effective chemical treatments are currently available to home gardeners in the UK; prevention via collars is the primary approach.
Disease Clubroot Plasmodiophora brassicae
Symptoms: Distorted, swollen and club-shaped roots; plants wilt in warm weather and recover at night; leaves turn yellow and growth is severely stunted.
Treatment: No cure once infected. Remove and destroy all affected plant material — do not compost. Raise soil pH to 7.5 or above with lime before replanting.
Prevention: Avoid bringing in infected soil or plants; practise a minimum four-year brassica rotation; lime acid soils before planting.
Disease Downy Mildew Peronospora parasitica
Symptoms: Yellow patches on upper leaf surface with a grey-white downy mould on the underside; leaves turn brown and die off; seedlings can collapse.
Treatment: Remove and destroy affected leaves promptly. Improve air circulation by spacing plants adequately. Apply a copper-based fungicide as a preventive spray.
Prevention: Avoid overhead watering; maintain good spacing; remove plant debris promptly at the end of the season.
Growing Conditions
| Min. soil temperature | 5°C |
| Germination temperature | 15–25°C |
| Base growth temperature | 5°C |
| Min. daylength to start | 8h |
| Photoperiod sensitivity | day neutral |
Frequently Asked Questions
- How far apart should I plant Sprouting Broccoli?
- Plant Sprouting Broccoli 60cm apart with 60cm between rows.
- When can I harvest Sprouting Broccoli?
- Sprouting Broccoli is ready to harvest approximately 220 days after transplanting.
- Is Sprouting Broccoli frost hardy?
- Sprouting Broccoli is classified as Hardy.
