When should I plant zucchini in ZIP 85201?

In ZIP 85201, the main zucchini target is around Feb 15, based on the representative Phoenix frost station and USDA zone 10a.

When should I start zucchini seeds indoors in 85201?

Start zucchini seeds indoors in ZIP 85201 around Jan 15, about 21 days before the Feb 5 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 85201 planting calendar

When to plant zucchini in Mesa, AZ - Zone 10a

Q: When is the first frost in Mesa?

Mesa (ZIP 85201) has an average first fall frost around Dec 15, leaving about 313 frost-free days.

In ZIP 85201, plant zucchini around Feb 15; this uses the Phoenix frost station, USDA zone 10a, and zucchini timing rules.

Your Phoenix calendar has a 313-day estimated frost-free season. This estimate uses the representative Phoenix frost station, USDA zone 10a, and zucchini timing rules.

Source: phoenix-skyharbor frost station, USDA zone 10a, 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 10a Phoenix frost station University of Arizona Extension Updated 2026-06-28

Read the method

Answer first

When to start zucchini seeds indoors in Mesa

In ZIP 85201, start zucchini seeds indoors around Jan 15, about 21 days before the Feb 5 last-frost estimate.

Start zucchini seeds indoors in Mesa around Jan 15, about 21 days before the Feb 5 last-frost estimate.

Seed starting schedule

Zucchini dates for Mesa, AZ

Step	Date	How to use it
Start Indoors	January 15, 2026	Start seeds under lights or in a bright indoor seed-starting space.
Transplant Outdoors	February 15, 2026	Move hardened-off seedlings outside after the frost-risk window.
Direct Sow	February 15, 2026	Sow seed outside when the crop and soil can handle the window.

Last frost

When is the last frost in Mesa?

Mesa (ZIP 85201) has an average last spring frost around Feb 5.

First frost

When is the first frost in Mesa?

The average first fall frost is around Dec 15, giving about 313 frost-free days.

Season map

Zucchini windows by month

JanFebMarAprMayJunJulAugSepOctNovDec

Start indoors

Jan 15

Direct sow

Feb 15

Transplant

Feb 15

Harvest

Apr 11

Frost watch

Oct 21

Reminder workflow

Every date has a next action

Start zucchini indoorsJan 15

Last frost windowFeb 5

Direct sow zucchiniFeb 15

Transplant zucchiniFeb 15

First zucchini harvest windowApr 11

Last zucchini sowing targetOct 21

Signal	Value	Why it matters
Last frost estimate	February 5, 2026	Warm-season transplant risk starts falling after this window.
First frost estimate	December 15, 2026	Fall planting counts backward from this date.
Season length	313 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

Phoenix frost history and USDA zone 10a shift the safe planting window. GrowZone uses a local representative station instead of one national rule.

University of Arizona 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 Dec 15. A conservative last sowing target is around Oct 21.