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ZIP 85201 planting calendar

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

In ZIP 85201, plant peppers around Feb 19; this uses the Phoenix frost station, USDA zone 10a, and peppers 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 peppers 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 peppers seeds indoors in Mesa

In ZIP 85201, start peppers seeds indoors around Dec 11, about 56 days before the Feb 5 last-frost estimate.

Start peppers seeds indoors in Mesa around Dec 11, about 56 days before the Feb 5 last-frost estimate.

Seed starting schedule

Peppers dates for Mesa, AZ

StepDateHow to use it
Start IndoorsDecember 11, 2025Start seeds under lights or in a bright indoor seed-starting space.
Transplant OutdoorsFebruary 19, 2026Move hardened-off seedlings outside after the frost-risk 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

Peppers windows by month

JanFebMarAprMayJunJulAugSepOctNovDec
Start indoors
Dec 11
Transplant
Feb 19
Harvest
May 15
Frost watch
Sep 21

Reminder workflow

Every date has a next action

Start peppers indoorsDec 11
Last frost windowFeb 5
Transplant peppersFeb 19
First peppers harvest windowMay 15
Last peppers sowing targetSep 21
SignalValueWhy it matters
Last frost estimateFebruary 5, 2026Warm-season transplant risk starts falling after this window.
First frost estimateDecember 15, 2026Fall planting counts backward from this date.
Season length313 daysLonger seasons can support succession crops.
Spacing18 inAirflow and root space affect yield.
Soil temperature65 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

Peppers timing notes

Peppers stall in cold soil, so wait for warm nights. Peppers prefers full sun, 18 in spacing, and soil near 65 F+.

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