Homegrown broccoli is sweeter and more tender than store-bought, and after you cut the main head, most varieties keep producing smaller side shoots for weeks. Broccoli is a cool-season crop that needs rich soil and steady moisture, and it forms its best heads in cool weather. This page covers when to plant for spring and fall, how to space and feed it, and how to tell when a head is ready.
Broccoli at a glance
| Type | Vegetable |
|---|---|
| Season | Cool-season |
| Sun | Full sun |
| Plant spacing | 18 in |
| Row spacing | 30 in |
| Per square foot | 1 |
| Seed depth | ½ in |
| Days to maturity | 55–80 from transplant |
| How to start | Indoors 6–8 weeks before last frost |
| Water | 1 in per week |
These are the same numbers our plant spacing, square foot and harvest date calculators use. See every crop in the plant database.
When to plant broccoli
For spring, start seeds indoors 6 to 8 weeks before your last spring frost and plant out 2 to 4 weeks before it; young plants tolerate light frost. The aim is for heads to form before summer heat, which makes them loose and flowery. Fall is often the better season: start seeds in midsummer and plant out about 10 to 12 weeks before your first fall frost, so heads mature in cool weather.
Find your dates with the frost dates by ZIP code tool, and the seed starting calculator counts back to your indoor sowing date.
How to plant broccoli
- Choose full sun. At least 6 hours a day.
- Feed the soil. Broccoli is a heavy feeder. Work 2 to 3 inches of compost into the bed.
- Plant transplants a little deeper. Set them so the lowest leaves sit just above the soil, and firm the soil well.
- Use young transplants. Plant when seedlings have 4 to 6 true leaves. Older, root-bound transplants tend to form tiny early heads.
- Space properly and rotate. Use the spacing in the table above, and avoid spots where cabbage-family crops grew recently. The crop rotation checker helps.
Caring for broccoli
Give about an inch of water a week and keep the soil evenly moist, especially while heads form. Water at the base and mulch to keep roots cool. The garden watering calculator turns this into gallons.
Side-dress with a nitrogen-rich fertilizer or compost about 3 weeks after transplanting and again when heads begin to form. Cover plants with row cover after planting to keep cabbage worms and flea beetles off; broccoli does not need pollinating, so the cover can stay on.
Companion plants
| Grow nearby | Onions, garlic, dill, chamomile, celery, beets, lettuce, nasturtiums |
|---|---|
| Keep apart | Strawberries; tomatoes and pole beans (compete for nutrients and light) |
Onions and garlic help confuse cabbage pests, and dill attracts the wasps that prey on cabbage worms. Lettuce and beets fit around broccoli without competing much. Check other pairings with the companion plant finder.
Common problems
| Problem | What you see | What to do |
|---|---|---|
| Cabbage worms and loopers | Green caterpillars on leaves and hidden in heads | Use row cover, hand-pick caterpillars or spray Bt. Soak harvested heads in salt water to float out hidden worms. See the pest identifier. |
| Buttoning | Plants form tiny heads very early | Caused by stress: root-bound transplants, cold snaps or dry soil. Plant young transplants and keep them watered. |
| Loose, flowering heads | Heads open into yellow flowers before they size up | Heat. Time plantings so heads form in cool weather, and harvest promptly. |
| Aphids | Gray, waxy clusters under leaves and in heads | Spray off with water and encourage ladybugs. |
| Clubroot | Plants wilt on warm days; roots swollen and distorted | Rotate cabbage-family crops for several years and raise soil pH toward 7.2 with lime. |
Not sure what you are looking at? The plant problem identifier ranks likely causes from the symptoms you see, and our guide to growing broccoli goes into more detail.
When and how to harvest
Cut the main head when it is firm and the buds are tight and dark green, before any yellow flowers appear. Head size varies by variety, usually 4 to 8 inches across. Cut the stem at an angle about 5 to 6 inches below the head, so water runs off the cut.
Leave the plant in place. Most varieties then send up side shoots with small heads for several more weeks; pick these regularly too. Harvest in the morning, and store unwashed broccoli in the fridge for up to a week. Use the harvest date calculator to estimate when heads will be ready.
Plan your broccoli
- Plant spacing calculator: how many plants fit your bed
- Planting calendar: sowing and transplant dates for your frost dates
- Frost dates by ZIP code: your last spring and first fall frost
- Harvest date calculator: when your crop will be ready
Frequently asked questions
How far apart should I plant broccoli?
Space broccoli 18 inches apart in rows 30 inches apart. In a square foot garden, plant 1 per square foot.
How deep do I plant broccoli seeds?
Sow seeds ½ inch deep. Set transplants slightly deeper than they grew, with the lowest leaves just above the soil.
How long does broccoli take to grow?
Most varieties are ready 55–80 days from transplant. Check the seed packet, because early and late varieties differ.
How much water does broccoli need?
About 1 inch of water a week, from rain and watering combined. Keep the soil evenly moist, especially while heads are forming.
Why is my broccoli flowering before it forms a head?
Heat and stress make broccoli bolt. Time plantings so heads form in cool weather, keep plants watered and harvest as soon as heads are firm.
Does broccoli grow back after cutting?
Most varieties produce smaller side shoots for several weeks after you cut the main head. Leave the plant in place and keep picking.