PlantWhy

Broccoli

Brassica oleracea var. italica · Vegetable

A cool-season crop grown for its tight green heads and the smaller side shoots that follow. Heat makes it flower early, so spring and autumn crops do best. Rich soil and steady moisture give the biggest, tenderest heads.

Broccoli
Photo: U.S. Department of Agriculture, Public domain · Wikimedia Commons
💧Water1–1.5 in per week, evenly (estimated)
☀️LightFull sun, 6+ hours
🐾PetsNot toxic

Care at a glance

Light
Full sun, at least 6 hours
Water
1–1.5 in per week, evenly
Soil
Fertile, moisture-retentive, well-drained, pH 6.0–7.0
Temperature
Best 60–70 °F; heads loosen above 80 °F
Spacing
18 in apart, rows 24–36 in apart
Container
At least 5 gallons, 12 in deep, one plant each
Harvest
60–90 days after transplanting (estimated)
Lifespan
Annual (biennial grown as annual)

When?

Start seeds indoors 6–8 weeks before the last spring frost and plant out 2–3 weeks before it. For an autumn crop, sow in midsummer so heads form in cool weather (estimated).

Step by step

  1. Sow seeds 1/4–1/2 in deep in cell trays; they sprout in 5–10 days.
  2. Harden off seedlings for a week before planting out.
  3. Plant firmly, slightly deeper than in the tray, in compost-rich soil.
  4. Cover with fine netting to keep out cabbage butterflies and birds.
  5. Water evenly and mulch; stress causes small, early heads.
  6. Side-dress with a nitrogen-rich feed about 3 weeks after planting.
  7. Cut the main head while buds are tight and still green.
  8. Keep watering after the first cut to get a crop of side shoots.

Common problems

Green caterpillars on leavesCabbage worms; use netting and hand-pick or apply a Bt spray.
Tiny heads form earlyHeat or transplant stress; plant at the right time and keep moist.
Heads turning yellowHarvested too late; cut while buds are still tightly closed.
Wilting plants with swollen rootsClubroot; rotate crops and raise soil pH with lime.

Pets

Broccoli is not listed as toxic for cats or dogs. If in doubt, ask your vet.

Related tools

Planting calendarSoil and mulch calculator

Similar plants

CauliflowerCabbageSpinach

Sources

This page is general guidance; no pesticide doses are given.