When to plant broccoli by city
Start broccoli indoors 6–8 weeks before your last frost, plant them out 2–4 weeks before your last frost. For a fall crop, sow 10–14 weeks before your first fall frost. Here is what that means for 2027 in cities across the US, using each city’s average frost dates (NOAA 1991–2020). Pick the city with the climate most like yours, or enter your ZIP code above.
| City | Last frost | Start indoors | Plant out | Fall crop |
|---|---|---|---|---|
| Seattle, WA (9a) | Mar 13 | Jan 16–30 | Feb 13–27 | Aug 11 – Sep 8 |
| Portland, OR (8b) | Feb 25 | Dec 31 – Jan 14 | Jan 28 – Feb 11 | Aug 25 – Sep 22 |
| Sacramento, CA (9b) | Jan 12 | Nov 17 – Dec 1 | Dec 15–29 | Sep 9 – Oct 7 |
| Phoenix, AZ (10a) | Jan 5 | Nov 10–24 | Dec 8–22 | Sep 27 – Oct 25 |
| Salt Lake City, UT (7b) | Mar 31 | Feb 3–17 | Mar 3–17 | Aug 2–30 |
| Denver, CO (6a) | Apr 30 | Mar 5–19 | Apr 2–16 | Jul 6 – Aug 3 |
| Dallas, TX (8b) | Mar 2 | Jan 5–19 | Feb 2–16 | Aug 23 – Sep 20 |
| Minneapolis, MN (5a) | Apr 23 | Feb 26 – Mar 12 | Mar 26 – Apr 9 | Jul 10 – Aug 7 |
| Kansas City, MO (6b) | Apr 4 | Feb 7–21 | Mar 7–21 | Jul 27 – Aug 24 |
| Chicago, IL (6b) | Apr 10 | Feb 13–27 | Mar 13–27 | Jul 30 – Aug 27 |
| Columbus, OH (6b) | Apr 20 | Feb 23 – Mar 9 | Mar 23 – Apr 6 | Jul 18 – Aug 15 |
| Nashville, TN (7b) | Apr 1 | Feb 4–18 | Mar 4–18 | Jul 25 – Aug 22 |
| Atlanta, GA (8a) | Mar 24 | Jan 27 – Feb 10 | Feb 24 – Mar 10 | Aug 2–30 |
| Raleigh, NC (8a) | Mar 28 | Jan 31 – Feb 14 | Feb 28 – Mar 14 | Aug 2–30 |
| Philadelphia, PA (7b) | Mar 30 | Feb 2–16 | Mar 2–16 | Aug 11 – Sep 8 |
| Boston, MA (7a) | Apr 4 | Feb 7–21 | Mar 7–21 | Aug 3–31 |
In frost-free parts of Florida, southern California and the Gulf Coast, timing is about heat instead: grow broccoli from fall through winter.
Broccoli spacing
In a square-foot bed, plant 1 per square foot. In traditional rows, space plants about 18 inches apart with 30 inches between rows.
Bolts in heat. In warm areas a fall crop is easier than spring.
How to grow broccoli
Broccoli is a cool-season crop that turns bitter and bolts in summer heat. In the North it does well planted in early spring; in warm regions a fall crop is far easier, maturing as the weather cools. Many varieties keep producing side shoots for weeks after the main head is cut.
Sun and soil
Full sun and fertile, well-drained soil rich in organic matter, pH about 6.0–7.0. Keep moisture steady, around 1–2 inches a week.
Planting
- Start seeds indoors 6–8 weeks before transplanting, ¼–½ inch deep.
- Transplant 2–4 weeks before the last spring frost, when soil is at least 45°F. Use stocky plants with 4–6 leaves; older, root-bound transplants tend to form tiny early heads.
- Space plants 18 inches apart in rows 30 inches apart.
- For fall, set out transplants 10–14 weeks before your first fall frost.
Care
- Water deeply and evenly; stress during head formation causes small or loose heads.
- Side-dress with nitrogen 3–4 weeks after transplanting.
- Mulch to keep roots cool and moist as spring warms.
- After cutting the main head, keep watering and feed lightly to encourage side shoots.
Harvest
Cut the main head while the buds are tight and dark green, before any yellow flowers show. Size depends on variety. Cut the stem about 5–6 inches below the head. Side shoots are smaller, 1–3 inches across, and should be picked every few days.
Common problems
- Cabbageworms and loopers: Green caterpillars chewing leaves and hiding in heads. Use row cover from planting, hand-pick, or spray Bt while they are small.
- Aphids: Gray, waxy clusters on leaves and in heads. Blast them off with water or use insecticidal soap before heads form.
- Buttoning (tiny early heads): Caused by cold snaps, drought or overgrown transplants. Plant young transplants on time and keep them watered and fed.
- Hollow stem: Linked to fast growth from excess nitrogen and to boron shortage. Use moderate fertilizer and follow soil test advice.
Varieties to try
- 'Packman' — early, large heads, good side shoots
- 'Green Magic' — tolerates heat better than most
- 'Belstar' — dependable for spring or fall
- 'De Cicco' — Italian heirloom with many side shoots
Crop rotation
Broccoli belong to the cabbage family (Brassicaceae). Clubroot and cabbage pests build up in the soil. Rotate for at least 3 years. Relatives that count as the same family for rotation: cauliflower, cabbage, kale, brussels sprouts, radish, turnip, arugula, bok choy, kohlrabi.
Frequently asked questions
When should I plant broccoli?
What grows well with broccoli?
What should not be planted with broccoli?
How far apart should I plant broccoli?
How long do broccoli take to grow?
Can broccoli handle frost?
Sources
- Frost dates: NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020.
- Hardiness zones: 2023 USDA Plant Hardiness Zone Map, USDA-ARS and PRISM Climate Group, Oregon State University.
- Planting windows and spacing: Vegetable Planting Guide (GardenNotes #720), Colorado State University Extension, and other land-grant extension guides.
- Gardening with Companion Plants (EM128E), Linda Chalker-Scott, Washington State University Extension, 2023
- Brassica flea beetles, UMass Amherst Vegetable Program
- Trap Cropping, Washington State University Extension Master Gardener Program
- Trap cropping: a review of the state of the art, Sarkar et al., 2018 (open-access review)
- Broccoli — Clemson Cooperative Extension (HGIC)
- Broccoli in the Garden — Utah State University Extension