BroccoliBrassica oleracea var. italica

Broccoli likes sun and coolness, a pairing our temperate summers offer it naturally. Choose an open bed, in deep, moist soil, loamy or clay, sheltered from drying winds; avoid the foot of a south-facing wall, which cooks the heads in August. Like all cabbages, it demands a rotation of four to five years without brassicas, radishes and rocket included. The summer plants find their place after peas or broad beans, those of purple sprouting broccoli, which overwinter, after early potatoes or garlic, in July.

Add four kilos of mature compost per square metre the previous autumn or a month before planting, worked in to twenty-five centimetres. Broccoli is less demanding than cauliflower, but poor soil gives small heads that flower straight away. On acid soil, lime lightly in autumn. Fork over, remove perennial weeds, then firm the surface with the rake: firm soil gives stable plants, able to carry the head without toppling. Soil that stays cool in summer matters more to broccoli than very rich soil.

For a June-July harvest, sow in February-March under cover at 15 °C, in a seed tray, then in pots. For summer and autumn, the most generous period, sow in an outdoor seedbed under mesh from April to mid-June, in rows ten centimetres apart, one centimetre deep, in two or three batches three weeks apart. For purple sprouting broccoli, sow in May-June. The classic calabrese varieties give a large head and then shoots; modern varieties such as Marathon or Ironman are more uniform. Sprouting broccolis, green or purple, produce small florets in abundance.

Thin to five centimetres or prick out into eight-centimetre pots at the two-true-leaf stage. Plant five to six weeks after sowing, when the plant has five leaves, without letting it age in its pot: a stressed broccoli forms a tiny head that runs to flower. Space fifty centimetres apart, sixty between rows, seventy for purple sprouting broccoli, which grows large. Bury up to the first leaves, firm well, water three litres per plant. A collar against the cabbage root fly and insect-proof mesh over hoops from planting.

Broccoli produces its head over a short period, then shoots for a month: to have it all summer and autumn, plant three times, in May, June and mid-July, six plants each time. Avoid July plantings in full sun on dry soil, unless you shade and water seriously. The last planting, in mid-July, gives heads in October, when the cool weather makes them particularly tight. Add a row of purple sprouting broccoli, planted in July, for a harvest from March to May, at a time when the vegetable garden offers almost nothing else.

Broccoli succeeds in a container of thirty litres and forty centimetres deep per plant, filled with potting compost enriched with a third of garden compost and well firmed. Place in the morning sun, in afternoon shade during a heatwave, and water every day in summer: the head only forms properly if the compost stays moist. Feed with plant liquid every two weeks. A fleece thrown over hoops protects against the cabbage white. Compact or sprouting varieties are best suited; expect a medium head and thirty or so shoots per container plant.

Letting the soil dry out in July, even for a few days, produces a head the size of a golf ball that flowers within the week. Planting plants that are too old, yellowed in their pots, has the same effect. Harvesting too late, when the buds have yellowed, gives a stringy, bland vegetable: check every two days. Pulling up the plant after the central head means forgoing half the harvest, the shoots. Finally, forgetting the mesh means harvesting heads stuffed with caterpillars and aphids, hard to clean.

Water every two days for two weeks after planting, then fifteen litres per square metre once or twice a week in summer, at the base, in the morning, without wetting the heads. While the head is forming, about a month before harvest, never let the soil dry out: this is when drought stress triggers premature flowering. A thick mulch halves the need. In autumn, rain is enough; purple sprouting broccoli needs nothing in winter and even fears excess water.

Three weeks after planting, mulch six to eight centimetres deep with dried grass clippings, straw or leaves, keeping the collar clear. Feed with nettle or comfrey liquid diluted to 10 % three weeks after planting, then every three weeks until the head appears, one watering can for two plants. Then stop the nitrogen, which would give loose heads. After harvesting the central head, a last watering of plant liquid restarts the production of shoots. For purple sprouting broccoli, nothing more after September, and a little compost in March.

A month after planting, hoe and draw five centimetres of soil against the stem to steady the plant, which becomes heavy with leaves. Repeat in late summer for purple sprouting broccoli, which must hold up all winter and benefits from staking in an exposed position. Remove yellow leaves from the bottom. Do not fold the leaves over the head as you would for cauliflower: broccoli needs light to stay nicely green and tight. Only protect the heads of August plantings from scorching sun with a fleece.

The cabbage white is the first enemy, from June to September: insect-proof mesh over hoops from planting to harvest, or weekly inspection under the leaves, eggs crushed, caterpillars picked off. Mealy cabbage aphids lodge in the heart of the florets, where they are hard to dislodge: hose off, soft soap diluted to 5 %, removal of infested florets, and soaking of harvested heads for ten minutes in salted water. A collar against the cabbage root fly. Rotation, liming and drainage against clubroot. Purple sprouting broccoli in winter calls for a net against pigeons from December.

In February-March, sow under cover for summer. In April-May, sow in a seedbed under mesh, plant the first plants in late May. In June, plant the second batch, mulch, feed, hunt slugs. In July, plant the third batch and the purple sprouting broccoli, water without fail, harvest the first heads. In August-September, harvest heads and shoots, feed after each head, watch for aphids and caterpillars. In October-November, harvest the last heads, earth up the winter broccoli. From December to February, net against pigeons. In March-May, harvest the purple shoots every three days.

Cut the central head with a knife, at an angle, with ten centimetres of stem, as soon as it is nicely compact and the buds are tight and blue-green, before the slightest yellowing. An angled cut stops water sitting on the stem and rotting it. Leave the plant: side shoots appear in the axils for four to six weeks, to be picked every two or three days to stimulate more. Pick in the morning. Purple sprouting broccoli is harvested floret by floret from March to May, over several weeks, and its tender leaves can be cooked too. Pull up the plant as soon as it flowers.