How to Grow Cauliflower

Growing guide

Overview

Cauliflower is a cool-season brassica that forms a dense, white head called a curd. It’s slower and fussier than broccoli or cabbage, but homegrown heads taste sweeter and milder than anything from the store. It needs steady cool weather, consistent moisture, and full sun to form a tight, unblemished head.

Soil & planting prep

Work in 2–3 inches of compost or aged manure into a loamy, well-drained bed. Cauliflower prefers a soil pH of 6.0–7.0; add lime if your soil is more acidic. Space transplants 18–24 inches apart in rows 24–30 inches apart, and set them at the same depth they were growing in their pots.

When to plant

Start seeds indoors 6 weeks before your last frost date. Transplant seedlings outdoors 2–3 weeks before the last frost date, when daytime temperatures are around 60–70°F. In hot-summer regions, grow cauliflower as a fall crop by starting seeds in midsummer for a fall harvest.

How to plant

1. Start seeds indoors 6 weeks before your last frost date in seed-starting mix, keeping soil at 65–70°F.
2. Harden off seedlings over 7–10 days by setting them outside for gradually longer periods.
3. Prepare the bed with compost and a balanced fertilizer; cauliflower is a heavy feeder.
4. Transplant 2–3 weeks before the last frost date, spacing plants 18–24 inches apart and rows 24–30 inches apart.
5. Water deeply after transplanting and keep the soil consistently moist, not soggy.

5 common mistakes to avoid

• Planting too late in spring so heads mature in summer heat — cauliflower needs cool weather, so time it to finish before temperatures regularly exceed 75°F.
• Letting the soil dry out; drought stress causes small, loose, or ‘ricey’ curds, so water deeply once or twice a week.
• Skipping blanching — if you don’t tie the outer leaves over the head when it’s 2–3 inches across, the curd turns yellow, purple, or green and loses its mild flavor.
• Growing in too-small containers or crowded spacing, which stunts plants and prevents proper head formation; give each plant at least 5 gallons of soil and 18 inches of space.
• Harvesting too late — waiting until the curd loosens and separates ruins texture, so cut while it’s still tight and compact.

Harvesting & storage

Harvest when the head is tight, firm, and 6–8 inches across, before the curds start to separate or turn brown. Cut the stem just below the head with a sharp knife, leaving a few outer leaves attached. Store in a plastic bag in the refrigerator for up to two weeks.

Companion planting

Good companions include beans, peas, and aromatic herbs like dill and mint. Avoid planting near tomatoes, which compete heavily for nutrients and can stunt cauliflower growth.

Growing in containers

Cauliflower can grow in containers if you use at least a 5-gallon pot per plant with rich potting mix and consistent watering. Place it in full sun and be extra careful not to let the container dry out, since cauliflower is sensitive to moisture swings.

Pro tips

Start indoors 6 weeks before last frost; transplant 2-3 weeks before last frost. Blanch heads by tying leaves over them once they're 2-3 inches across. Harvest before curds loosen.