When to plant broccoli in Hawaii
Hawaii is essentially frost-free (USDA zones 9b, 10a, 10b, 11a, 11b, 12a, 12b, 13a), so broccoli timing there is set by heat and daylength rather than frost. As a cool-season crop, it does best in the cooler months (roughly October–March) and tends to bolt in summer heat.
Hawaii covers a wide range of climates, so your exact frost dates may differ from the state average by two weeks or more. For dates tuned to your town, use the calendar generator.
When to plant broccoli in Hawaii: the short answer
For a spring planting, plant out Jan 11 – Jan 28, with seeds started indoors Dec 14 – Dec 28. Seeds germinate in soil from 45 to 85°F.
Your area is essentially frost-free, so planting dates are set by heat and daylength rather than frost. Treat the ranges below as broad season guides.
Cool-season crop: in a frost-free area grow it in the cooler months (roughly October to March) and expect bolting in summer heat.
Windows are ~1–2 week bands around each date. Frost dates are a statewide average from NOAA/NCEI normals; your town may differ by two weeks or more. Calendar year 2026.
How to grow broccoli in Hawaii, step by step
- Start seeds indoors (Dec 14 – Dec 28). Sow seeds ½ inch deep in seed-starting mix under bright light. They take 5-10 days to sprout, fastest in soil around 75°F. Harden seedlings off for a week before they go outside.
- Prepare the bed. It needs at least six to eight hours of direct sun a day and loose soil at least 18 inches deep, with a pH between 6.0 and 7.0. Dig in compost before planting.
- Plant out (Jan 11 – Jan 28). Space plants about 18 inches apart in rows 30 inches apart. It tolerates a light frost but not a hard freeze. As a cool-season crop it does best before summer heat arrives in Hawaii.
- Water and feed. Give it steady, even moisture, about an inch of water a week from rain or the hose.
- Watch for pests and problems. Pests: cabbage worm, cabbage looper, aphids, flea beetle, cabbage root maggot. Diseases and disorders: clubroot, black rot, downy mildew.
- Harvest (from about Mar 19 – Apr 13). Broccoli takes 60-85 days to reach harvest. Days to maturity counted from transplant. Keep cutting side shoots after the main head for weeks. Spring crop must size up before heat or it buttons.
Figures come from our crop data; dates use Hawaii’s average frost dates. More in the full broccoli growing guide.