Broccoli

Sun

Full sun, ideally at least 6 hours daily; light afternoon shade can help in warm climates.

Water

Keep evenly moist, supplying about 1-1.5 in (25-40 mm) of water weekly, including rain; water more often in containers.

Soil

Fertile, moisture-retentive but well-drained soil with plenty of organic matter; aim for pH 6.5-7.5.

Height

2-3 ft (0.6-0.9 m); tall sprouting varieties may reach 4 ft (1.2 m)

Spread

1.5-2.5 ft (0.45-0.75 m)

Flowers

Yellow flowers in spring or summer if buds are left unharvested; timing depends on variety and sowing date.

Foliage

Large, waxy blue-green leaves with pale veins and lobed or wavy margins.

Growth

Fast in cool weather; heading varieties often crop about 8-14 weeks after transplanting, while overwintering sprouting…

Care needed

Medium

• Pollinators
• Low allergen
• Edible

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   0.5 ft (0.15 m)

2. After 1 year

   2.5 ft (0.75 m)

   full size

Full size in one season.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Mildly toxic: may upset a stomach

Native to

the UK

Growth rate

Fast

• Space plants 18-24 in (45-60 cm) apart, allowing more room for vigorous sprouting varieties.
• Water at soil level before the root zone dries out; avoid alternating drought and heavy watering.
• Mix compost into the bed before planting and apply a nitrogen-containing vegetable feed according to its label.
• Mulch around established plants to conserve moisture and suppress weeds, keeping mulch clear of the stems.
• Cover young plants with insect mesh, securing the edges against cabbage butterflies and moths.
• Stake tall overwintering plants in exposed gardens.

Pruning. Harvest the central head while its buds are tight, cutting with 4-6 in (10-15 cm) of stem before yellow flowers appear. Leave healthy leaves and side shoots in place, then harvest side shoots regularly.

Cut the main head when it is firm and compact, with tightly closed buds, before any yellow flowers open. Use a sharp knife to cut the stem 10–15 cm (4–6 in) below the head, leaving the lower leaves and plant in place. Many varieties then produce smaller side shoots; check every few days and pick these while their buds are still tightly closed.

Late winter

For a spring crop, sow heading broccoli indoors about 5-7 weeks before your intended planting date.

Spring

Harden off seedlings and transplant into prepared soil when workable; protect young plants from severe frost.

Late spring

Check under leaves weekly for caterpillars and eggs, maintain insect mesh, and harvest tight heads promptly.

Summer

Sow autumn-cropping varieties early enough to mature before hard freezes; sow overwintering sprouting types according to local guidance.

Autumn

Harvest autumn crops and stake overwintering sprouting plants before windy weather.

Winter

In mild climates, continue harvesting suitable varieties; elsewhere remove finished plants and plan a different bed for next year's brassicas.

• Plant in rows or blocks in a kitchen garden for straightforward access and harvesting.
• Use blue-green leaves as a bold foliage contrast beside lettuces and other low salad crops in a potager.
• Grow compact varieties in large containers on a sunny patio, allowing one plant per container.
• Place taller sprouting varieties toward the back of edible beds so they do not shade shorter vegetables.

Garden styles it suits: Potager (kitchen garden), Edible landscape, Homestead, Cottage garden, Farmhouse and Family-friendly.

Plant it with: Lettuce, Spinach, Radish, Beetroot, Dill and Sweet alyssum.

Wildlife: Unharvested yellow flowers provide nectar and pollen for bees and other insects. Leaves feed cabbage butterfly and moth caterpillars; birds may also peck young plants.

• Cabbage caterpillars chew holes in leaves and contaminate heads: use securely fitted insect mesh and hand-pick caterpillars and eggs.
• Cabbage root fly maggots damage roots, causing wilting: use insect mesh or snug stem collars from planting, and remove badly affected plants.
• Clubroot causes swollen roots and stunted growth: avoid moving contaminated soil, improve drainage, correct acidic soil after testing, and use resistant varieties where available.
• Small premature heads or loose, flowering heads follow stress: plant at the locally recommended time, avoid overgrown transplants, and maintain steady water and nutrition.

Heads, stems and leaves are edible for people and are not known to be toxic in normal food amounts. Broccoli is not generally considered poisonous to cats or dogs, but large servings can cause gas, vomiting or diarrhoea, and tough stems can be a choking hazard. Do not feed horses large amounts of broccoli or other brassicas, which can cause digestive problems and other illness.

• Broccoli raab (Brassica rapa)

  Has smaller, looser bud clusters and thinner, more deeply toothed leaves; it does not form a large central broccoli head.

• Cauliflower (Brassica oleracea var. botrytis)

  Forms a dense curd rather than clearly separated bead-like flower buds; curds may be white, orange, green or purple.

• Chinese broccoli (Brassica oleracea var. alboglabra)

  Grown mainly for thick, tender stems and smooth leaves, with small, loose bud clusters rather than a broad central head.

Broccoli comes from the Italian plural of broccolo, meaning a flowering shoot, while italica refers to its Italian association.

Propagation. Grow from seed, either in modules for transplanting or directly in the bed. Save seed only if you can manage cross-pollination with other flowering Brassica oleracea crops; hybrid varieties do not reliably come true from seed.

Accepted botanical name

Brassica oleracea Brassica oleracea var. italica is an older name for Brassica oleracea.

In the US and Canada

Introduced in the lower 48 states, Pacific Basin and Puerto Rico.

Native range

France, Great Britain and Spain.

Measured

Soil pH 7 to 7.5. Average height 50 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.