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Broccoli

One main head then weeks of side shoots, so a few plants feed a family for a season.

1. Sow in modules 1.5 cm deep and grow on at 15 to 18 C.
2. Transplant at 4 to 5 true leaves, burying the stem to the first leaves.
3. Firm the soil hard around each plant with your heel, brassicas need firm ground.
4. Space 45 cm apart and fit a 12 cm collar or mesh against root fly.
5. Water 25 mm weekly and feed a high-nitrogen liquid feed every fortnight.
6. Cut the central head while the beads are tight and still green.
7. Keep feeding and watering, side shoots follow for 4 to 8 more weeks.

Soil

Firm, rich, limed soil at pH 6.5 to 7.5. Loose soil gives blown heads.

Sun

Full sun, minimum 6 hours.

Water

25 mm a week, without fail while the head forms.

Spacing

45 cm apart, rows 60 cm

Depth

Sow 1.5 cm deep, plant out to the first true leaves

Care

['Stake tall autumn and winter plants, wind rock loosens the roots and stalls them.', 'Net against cabbage white butterflies from May to September.', 'Check leaf undersides weekly for yellow egg clusters and rub them off.', 'Earth up 10 cm around the stems in autumn for winter stability.']

Harvesting

Cut the main head with 15 cm of stem when the buds are tight, before any yellow shows. Cut in the morning. Side shoots then come from the leaf joints, pick these every few days.

Storing

1 week in the fridge unwashed. Blanch florets 3 minutes and freeze for 12 months. It does not store fresh for long, so freeze gluts on the day you cut.

Grow it next to

Beetroot, onions, dill and nasturtium as a trap crop. Keep away from strawberries and other brassicas.

Problems

[{'cause': 'Cut too late, or heat stress', 'fix': 'Cut when the beads are tight. In warm zones grow as an autumn and winter crop.', 'symptom': 'Head opens into yellow flowers'}, {'cause': 'Growth checked by drought, root disturbance or being pot-bound', 'fix': 'Plant out on time, water deeply, never let modules dry out.', 'symptom': 'Tiny loose button head on a small plant'}, {'cause': 'Cabbage white butterfly', 'fix': 'Net with 7 mm mesh held off the leaves, and pick off any caterpillars that get in.', 'symptom': 'Green caterpillars stripping the leaves'}, {'cause': 'Clubroot', 'fix': 'Lime to pH 7.2, raise big transplants in pots, and leave 7 years before brassicas return.', 'symptom': 'Plant wilts in sun and roots are swollen and stunted'}, {'cause': 'Constant heat above 28 C prevents heading', 'fix': 'Grow only in the coolest months or at altitude. In true lowland tropics broccoli often never heads and is best grown for leaves.', 'symptom': 'No head forms at all in a tropical garden'}]

Saving your own seed

Annual to biennial depending on type. It crosses freely with cabbage, kale, cauliflower and sprouts, so isolate by 1 km or cage the flowers. Let the pods dry brown on the plant.

Containers

Needs a 40 cm wide, 40 cm deep pot per plant and constant watering. Possible, but one plant fills a large pot for months for one head.