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ZIP 96813 planting calendar

When to plant carrots in Honolulu, HI - Zone 12b

In ZIP 96813, plant carrots around Dec 11; this uses the Honolulu frost station, USDA zone 12b, and carrots timing rules.

Your Honolulu calendar has a 364-day estimated frost-free season. This estimate uses the representative Honolulu frost station, USDA zone 12b, and carrots timing rules.

Source: honolulu-intl frost station, USDA zone 12b, last updated 2026-06-28. Verify locally before planting high-value crops because microclimates, current weather, and yard exposure can move the safe date.

USDA zone 12b Honolulu frost station University of Hawaii Cooperative Extension Updated 2026-06-28
Read the method

Answer first

When to start carrots seeds indoors in Honolulu

In ZIP 96813, carrots is usually direct-sown around Dec 11 instead of started indoors.

Carrots is normally direct-sown in Honolulu. Use around Dec 11 as the outdoor planting window for ZIP 96813.

Seed starting schedule

Carrots dates for Honolulu, HI

StepDateHow to use it
Direct SowDecember 11, 2025Sow seed outside when the crop and soil can handle the window.

Last frost

When is the last frost in Honolulu?

Honolulu (ZIP 96813) has an average last spring frost around Jan 1.

First frost

When is the first frost in Honolulu?

The average first fall frost is around Dec 31, giving about 364 frost-free days.

Season map

Carrots windows by month

JanFebMarAprMayJunJulAugSepOctNovDec
Direct sow
Dec 11
Harvest
Feb 19
Frost watch
Oct 22

Reminder workflow

Every date has a next action

Direct sow carrotsDec 11
Last frost windowJan 1
First carrots harvest windowFeb 19
Last carrots sowing targetOct 22
SignalValueWhy it matters
Last frost estimateJanuary 1, 2026Warm-season transplant risk starts falling after this window.
First frost estimateDecember 31, 2026Fall planting counts backward from this date.
Season length364 daysLonger seasons can support succession crops.
Spacing2-3 inAirflow and root space affect yield.
Soil temperature45 F+Seeds and transplants stall in cold soil.

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Local data

Why this date changes by ZIP

Honolulu frost history and USDA zone 12b shift the safe planting window. GrowZone uses a local representative station instead of one national rule.

University of Hawaii Cooperative Extension is the kind of local source to verify against when a crop is expensive, weather is unusual, or your yard has a cold pocket.

Crop note

Carrots timing notes

Direct sow only; carrots dislike transplanting. Carrots prefers full sun, 2-3 in spacing, and soil near 45 F+.

For fall, count backward from Dec 31. A conservative last sowing target is around Oct 22.