Hawaii planting calendar

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

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

Oregano planting timetable for Hawaii

Stage	When in Hawaii	Anchor
Direct-sow / set out (spring crop)	late January — early March	Frost-free — plant as soon as nights stay above 10 °C
Spring-crop harvest	~80 days later, before peak summer heat	80-day crop — finishes before mid-summer
Plant the fall crop	mid-August (August 15) — once the worst heat breaks	~94 days before the first fall frost (no frost)
Fall-crop harvest	early November into early winter	80-day crop — often the more productive of the two

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 oregano dates

Hawaii's long hot summer shuts down fruit set, so locals run two short crops — a spring planting and a fall planting — around a deliberate mid-summer pause, instead of one long northern-style season. Hawaii is frost-free at sea level and tropical year-round. Elevation, rainfall, and microclimate matter far more than any cold zone.

Oregano is a hardy perennial in zones 5-10 and is easiest to start from seed indoors 6-8 weeks before the last spring frost, or from divisions or cuttings; seeds are tiny and slow to produce harvestable growth. Transplant outdoors around the last frost date once soil has warmed to at least 13 °C — established plants tolerate light frost. In zones 4 and colder, treat as an annual or overwinter divisions in a cold frame; in zones 9-11 it stays evergreen but may die back in intense summer heat without afternoon shade.

Frost-risk note

Frost is essentially absent — the limiting hazard here is summer heat, when oregano plant pollen goes sterile above ~32 °C.

Regional variation within Hawaii

the coastal lowlands of all islands (zone 13a) can start the spring crop weeks earlier and may garden almost year-round; the upper slopes of Mauna Kea and Haleakala (zone 9a) runs a shorter, more northern-style single season.

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

Pair the spring slot with other heat-lovers (peppers, squash, beans); use the cool October–February window for greens and brassicas.

Quick-grow guide

Sun: Full sun — 6+ hours direct.
Soil temperature for germination: 13-21 °C (55-70 °F).
Spacing: 8-12 inches (20-30 cm) between plants.
Days to harvest: ~80 days from planting out.

Frequently asked questions

When is the best time to plant oregano in Hawaii?

In Hawaii (mostly USDA zone 12b), set the spring crop out late January–March, harvest before peak summer heat, then plant a second crop mid-August for an autumn harvest. Avoid mid-summer. Oregano are cold-hardy — they tolerate frost and actively prefer cool weather, so they go in well before the last spring frost and bolt in summer heat.

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 oregano in Hawaii?

Yes. Hawaii's dominant zone 12b supports oregano — the key is timing. Oregano are cold-hardy — they tolerate frost and actively prefer cool weather, so they go in well before the last spring frost and bolt in summer heat.

Does the planting date change across Hawaii?

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

Pair the spring slot with other heat-lovers (peppers, squash, beans); use the cool October–February window for greens and brassicas.

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.