Hawaii planting calendar

When to plant cauliflower in Hawaii — sow, transplant & harvest dates

Hawaii is mostly USDA zone 12b (range 9a-13a). Dates below are derived from cauliflower's frost tolerance and Hawaii's frost window — not generic national averages.

Cauliflower planting timetable for Hawaii

Stage	When in Hawaii	Anchor
Direct-sow / set out (main)	October — February	Grown through the cool season, not summer
Shoulder sowing	September and again late February	Avoid germinating into summer heat
First harvest	~85 days after sowing (late autumn through spring)	85-day crop

Dates are state-wide averages for the dominant zone. Local microclimates — elevation, urban heat, coastal moderation — can shift the window by 1-2 weeks. Use the frost-date calculator for a date tuned to your town.

Why Hawaii's climate shifts the cauliflower dates

Hawaii flips the calendar: its winter is the productive cauliflower season while northern states are frozen, and its summer is the off-season. Hawaii is frost-free at sea level and tropical year-round. Elevation, rainfall, and microclimate matter far more than any cold zone.

More temperature-sensitive than broccoli — optimal growing range is 15–18 °C (60–65 °F); temperatures above 27 °C (80 °F) cause loose, ricey curds, while a sharp frost below −3 °C (27 °F) can damage developing heads. Start indoors 6–8 weeks before last frost and transplant 2–3 weeks before last frost. Blanch white varieties by tying outer leaves over the curd when it reaches golf-ball size, or choose self-blanching types. Succession planting is difficult in spring in hot climates (zones 7+); fall crops from a midsummer sowing are often more reliable.

Frost-risk note

Frost is essentially a non-issue here — heat, not cold, ends the crop.

Regional variation within Hawaii

the coastal lowlands of all islands (zone 13a) can sow earliest in autumn and latest into late winter; the upper slopes of Mauna Kea and Haleakala (zone 9a) has a slightly shorter, frost-bracketed window.

Honolulu — USDA zone 12b
Hilo — USDA zone 12a
Kailua-Kona — USDA zone 12b
Lihue — USDA zone 12b

What else to plant in Hawaii around then

The same cool window suits other greens, brassicas, peas, carrots, and radishes — fill beds October through February.

Quick-grow guide

Sun: Full sun — 6+ hours direct.
Soil temperature for germination: 7–24 °C (45–75 °F).
Spacing: 18–24 inches (45–60 cm) between plants.
Days to harvest: ~85 days from planting out.

Frequently asked questions

When is the best time to plant cauliflower in Hawaii?

In Hawaii (mostly USDA zone 12b), grow cauliflower as a cool-season crop: direct-sow from October through February, harvest ~85 days later, and skip summer entirely — heat above 24 °C bolts it. Cauliflower are half-hardy — young plants shrug off a light frost but not a hard freeze, so sowing can start a couple of weeks before the last spring frost.

What USDA zone is Hawaii?

Most of Hawaii sits in USDA hardiness zone 12b, with the state spanning roughly 9a-13a from the upper slopes of Mauna Kea and Haleakala (zone 9a) to the coastal lowlands of all islands (zone 13a). The last spring frost averages no frost and the first fall frost no frost.

Can you grow cauliflower in Hawaii?

Yes. Hawaii's dominant zone 12b supports cauliflower — the key is timing. Cauliflower are half-hardy — young plants shrug off a light frost but not a hard freeze, so sowing can start a couple of weeks before the last spring frost.

Does the planting date change across Hawaii?

What else can I plant in Hawaii around the same time?

The same cool window suits other greens, brassicas, peas, carrots, and radishes — fill beds October through February.

Source and methodology

State zone spans from the USDA Plant Hardiness Zone Map (2023); frost-date averages from NOAA Climate Data Online. Hot-state two-season timing cross-checked against the UF/IFAS Florida Gardening Calendar and the University of Arizona Cooperative Extension planting calendar. Curated by the Growli editorial team.