When should I plant zucchini in ZIP 43215?

In ZIP 43215, the main zucchini target is around May 10, based on the representative Columbus frost station and USDA zone 6b.

When should I start zucchini seeds indoors in 43215?

Start zucchini seeds indoors in ZIP 43215 around Apr 9, about 21 days before the Apr 30 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 43215 planting calendar

When to plant zucchini in Columbus, OH - Zone 6b

Q: When is the first frost in Columbus?

Columbus (ZIP 43215) has an average first fall frost around Oct 15, leaving about 168 frost-free days.

In ZIP 43215, plant zucchini around May 10; this uses the Columbus frost station, USDA zone 6b, and zucchini timing rules.

Your Columbus calendar has a 168-day estimated frost-free season. This estimate uses the representative Columbus frost station, USDA zone 6b, and zucchini timing rules.

Source: columbus-port-columbus frost station, USDA zone 6b, 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 6b Columbus frost station Ohio State University Extension Updated 2026-06-28

Read the method

Answer first

When to start zucchini seeds indoors in Columbus

In ZIP 43215, start zucchini seeds indoors around Apr 9, about 21 days before the Apr 30 last-frost estimate.

Start zucchini seeds indoors in Columbus around Apr 9, about 21 days before the Apr 30 last-frost estimate.

Seed starting schedule

Zucchini dates for Columbus, OH

Step	Date	How to use it
Start Indoors	April 9, 2026	Start seeds under lights or in a bright indoor seed-starting space.
Transplant Outdoors	May 10, 2026	Move hardened-off seedlings outside after the frost-risk window.
Direct Sow	May 10, 2026	Sow seed outside when the crop and soil can handle the window.

Last frost

When is the last frost in Columbus?

Columbus (ZIP 43215) has an average last spring frost around Apr 30.

First frost

When is the first frost in Columbus?

The average first fall frost is around Oct 15, giving about 168 frost-free days.

Season map

Zucchini windows by month

JanFebMarAprMayJunJulAugSepOctNovDec

Start indoors

Apr 9

Direct sow

May 10

Transplant

May 10

Harvest

Jul 4

Frost watch

Aug 21

Reminder workflow

Every date has a next action

Start zucchini indoorsApr 9

Last frost windowApr 30

Direct sow zucchiniMay 10

Transplant zucchiniMay 10

First zucchini harvest windowJul 4

Last zucchini sowing targetAug 21

Signal	Value	Why it matters
Last frost estimate	April 30, 2026	Warm-season transplant risk starts falling after this window.
First frost estimate	October 15, 2026	Fall planting counts backward from this date.
Season length	168 days	Longer seasons can support succession crops.
Spacing	24-36 in	Airflow and root space affect yield.
Soil temperature	65 F+	Seeds and transplants stall in cold soil.

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Local data

Why this date changes by ZIP

Columbus frost history and USDA zone 6b shift the safe planting window. GrowZone uses a local representative station instead of one national rule.

Ohio State University 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

Zucchini timing notes

One or two healthy plants can feed a household. Zucchini prefers full sun, 24-36 in spacing, and soil near 65 F+.

For fall, count backward from Oct 15. A conservative last sowing target is around Aug 21.