How to Grow Broccoli

Overview

Broccoli is a highly nutritious brassica that can be grown in two main forms: calabrese (green heading broccoli for summer harvest) and sprouting broccoli (for late winter and spring picking). Sprouting broccoli is particularly valuable as it crops when fresh vegetables are scarce. Both types reward the patient gardener generously.

Health Benefits

Rich in sulforaphane: Broccoli is one of the best natural sources of sulforaphane, a compound that may support the body's natural detoxification processes and has been widely studied for its health-promoting properties.

Excellent source of Vitamins C and K: A generous serving of broccoli provides more than your daily Vitamin C needs, along with abundant Vitamin K for bone and blood health.

Fibre and folate: Broccoli is rich in dietary fibre for digestive health and folate for healthy cell growth and development.

Soil Preparation

Broccoli needs fertile, firm, well-drained soil with a pH of 6.5 to 7.5. Lime acidic soils in autumn if needed. Dig in well-rotted compost or manure several months before planting and firm the soil well. Brassicas are prone to club root in acidic, poorly drained conditions, so good soil preparation is essential.

Sowing & Planting

Sow calabrese from February to April indoors in modules, and plant out from April to June, spacing 45cm apart. For sprouting broccoli, sow from March to April and transplant in May to June. Plant deeply, burying the stem to the first set of leaves for stability. Net plants immediately to protect from pigeons.

Care & Maintenance

Water consistently during dry periods, especially when the heads are forming. Feed with a balanced fertiliser after transplanting and again when heads begin to develop. Stake tall sprouting broccoli plants in autumn to prevent wind rock. Earth up around stems for extra stability.

Harvesting

Cut calabrese heads while the buds are still tight and green, typically from July to October. After removing the central head, side shoots will develop for continued picking. Harvest sprouting broccoli from February to May, picking the spears when they are about 15cm long and before the flowers open.

Common Problems

Cabbage white butterfly caterpillars can devastate plants. Cover with butterfly netting and inspect regularly for eggs.

Club root causes swollen roots and stunted growth. Maintain soil pH above 7.0 and rotate brassica crops on a three-year cycle.

Pigeons strip leaves in winter. Net plants securely or use deterrent devices.

Companion Planting

Broccoli grows well alongside celery, dill, and rosemary, which can help deter cabbage pests with their strong aromas. Avoid planting near strawberries and tomatoes, which are poor companions for brassicas.