Broccoli

Brassica oleracea var. italica

The part you eat is a head of green flower buds. Once you cut the main head, side shoots keep coming for weeks. Pick before the buds open into yellow flowers, which happens fast in warm weather. Sprouting broccoli is a tougher kind that lasts through winter and gives its crop in spring.

Looking after it

Water: Broccoli needs normal watering. Water young plants regularly until they are settled, then in dry spells. If growth stalls, the plants flower early. A layer of compost over the soil keeps it moist. Feeding: It needs rich soil and plenty of food. Dig in compost or manure before planting. On poor soil, or if growth is slow, give a high-nitrogen feed when the plants are about 20 cm tall.

Harvest and keeping

Cut the main head with some stem while it is firm and the buds are still closed. Then check every few days and cut the side shoots before they flower. Regular picking keeps them coming for up to two months. Broccoli keeps a few days in the fridge. It freezes well once blanched.

What can go wrong

Early flowering. In hot weather, or when the plants stop growing for a while, the heads stay small and open into yellow flowers. Water in dry spells and, where summers are hot, grow bolt-resistant varieties, which are slow to flower. Cut the heads as soon as they are ready.
Caterpillars. From early summer to autumn, you see holes in the leaves and green caterpillars. Cover the plants with fine insect mesh from the day you plant them. Rub off any clusters of yellow eggs under the leaves.
Pigeons. Pigeons tear the leaves until only stalks and veins are left. Cover the plants with netting held clear of the leaves on hoops or canes.

Growing facts: RHS, UC ANR and seed-company sowing guides. Broccoli care and keeping: RHS. How many to grow: Kansas State and University of Missouri extension. pH: Washington State University extension. Pot size: Texas A&M AgriLife extension.