When to plant kale in Hawaii
Hawaii is essentially frost-free (USDA zones 9b, 10a, 10b, 11a, 11b, 12a, 12b, 13a), so kale 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 kale in Hawaii: the short answer
For a spring planting, sow Jan 6 – Jan 25, 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 kale 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 70°F. Harden seedlings off for a week before they go outside.
- Prepare the bed. It needs six or more hours of sun for the best growth, though four to six hours in partial shade is enough and loose soil at least 18 inches deep, with a pH between 6.0 and 7.5. Dig in compost before planting.
- Sow outdoors (Jan 6 – Jan 25). Space plants about 16 inches apart in rows 20 inches apart, sowing seed ½ inch deep. It tolerates hard frost, so it is one of the first crops to plant. 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, cabbage aphid, flea beetle, harlequin bug. Diseases and disorders: black rot, clubroot, downy mildew.
- Harvest (from about Mar 2 – Mar 17). Kale takes 50-65 days to reach harvest. Flavour turns sweet after a hard frost, so the fall crop is the good one. Pick lower leaves and let the plant keep growing upward.
Figures come from our crop data; dates use Hawaii’s average frost dates. More in the full kale growing guide.