When should I plant kale in ZIP 96813?

In ZIP 96813, the main kale target is around Dec 18, based on the representative Honolulu frost station and USDA zone 12b.

When should I start kale seeds indoors in 96813?

Start kale seeds indoors in ZIP 96813 around Nov 27, about 35 days before the Jan 1 last-frost estimate.

Is this a guaranteed planting date?

No. GrowZone uses frost-date estimates, hardiness zones, and crop timing rules for planning. Local microclimates and current weather can shift the right date.

ZIP 96813 planting calendar

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

Q: When is the first frost in Honolulu?

Honolulu (ZIP 96813) has an average first fall frost around Dec 31, leaving about 364 frost-free days.

In ZIP 96813, plant kale around Dec 18; this uses the Honolulu frost station, USDA zone 12b, and kale 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 kale 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 kale seeds indoors in Honolulu

In ZIP 96813, start kale seeds indoors around Nov 27, about 35 days before the Jan 1 last-frost estimate.

Start kale seeds indoors in Honolulu around Nov 27, about 35 days before the Jan 1 last-frost estimate.

Seed starting schedule

Kale dates for Honolulu, HI

Step	Date	How to use it
Start Indoors	November 27, 2025	Start seeds under lights or in a bright indoor seed-starting space.
Transplant Outdoors	December 18, 2025	Move hardened-off seedlings outside after the frost-risk window.
Direct Sow	December 11, 2025	Sow 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

Kale windows by month

JanFebMarAprMayJunJulAugSepOctNovDec

Start indoors

Nov 27

Direct sow

Dec 11

Transplant

Dec 18

Harvest

Feb 16

Frost watch

Nov 1

Reminder workflow

Every date has a next action

Start kale indoorsNov 27

Direct sow kaleDec 11

Transplant kaleDec 18

Last frost windowJan 1

First kale harvest windowFeb 16

Last kale sowing targetNov 1

Signal	Value	Why it matters
Last frost estimate	January 1, 2026	Warm-season transplant risk starts falling after this window.
First frost estimate	December 31, 2026	Fall planting counts backward from this date.
Season length	364 days	Longer seasons can support succession crops.
Spacing	12-18 in	Airflow and root space affect yield.
Soil temperature	45 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

Kale timing notes

Kale sweetens after a light frost. Kale prefers full sun, 12-18 in spacing, and soil near 45 F+.

For fall, count backward from Dec 31. A conservative last sowing target is around Nov 1.