GrowZone

ZIP 53202 planting calendar

When to plant spinach in Milwaukee, WI - Zone 6a

In ZIP 53202, plant spinach around Apr 12; this uses the Milwaukee frost station, USDA zone 6a, and spinach timing rules.

Your Milwaukee calendar has a 153-day estimated frost-free season. This estimate uses the representative Milwaukee frost station, USDA zone 6a, and spinach timing rules.

Source: milwaukee-mitchell frost station, USDA zone 6a, 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 6a Milwaukee frost station University of Wisconsin Extension Updated 2026-06-28
Read the method

Answer first

When to start spinach seeds indoors in Milwaukee

In ZIP 53202, spinach is usually direct-sown around Apr 12 instead of started indoors.

Spinach is normally direct-sown in Milwaukee. Use around Apr 12 as the outdoor planting window for ZIP 53202.

Seed starting schedule

Spinach dates for Milwaukee, WI

StepDateHow to use it
Direct SowApril 12, 2026Sow seed outside when the crop and soil can handle the window.

Last frost

When is the last frost in Milwaukee?

Milwaukee (ZIP 53202) has an average last spring frost around May 10.

First frost

When is the first frost in Milwaukee?

The average first fall frost is around Oct 10, giving about 153 frost-free days.

Season map

Spinach windows by month

JanFebMarAprMayJunJulAugSepOctNovDec
Direct sow
Apr 12
Harvest
May 27
Frost watch
Aug 26

Reminder workflow

Every date has a next action

Direct sow spinachApr 12
Last frost windowMay 10
First spinach harvest windowMay 27
Last spinach sowing targetAug 26
SignalValueWhy it matters
Last frost estimateMay 10, 2026Warm-season transplant risk starts falling after this window.
First frost estimateOctober 10, 2026Fall planting counts backward from this date.
Season length153 daysLonger seasons can support succession crops.
Spacing4-6 inAirflow and root space affect yield.
Soil temperature40 F+Seeds and transplants stall in cold soil.

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Local data

Why this date changes by ZIP

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

University of Wisconsin 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

Spinach timing notes

Plant early and again in late summer for fall leaves. Spinach prefers sun to part shade, 4-6 in spacing, and soil near 40 F+.

For fall, count backward from Oct 10. A conservative last sowing target is around Aug 26.