When should I plant spinach in ZIP 60601?

In ZIP 60601, the main spinach target is around Mar 28, based on the representative Chicago frost station and USDA zone 6a.

When should I start spinach seeds indoors in 60601?

Spinach is usually direct-sown for ZIP 60601. Use the Mar 28 planting window instead of starting it indoors.

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 60601 planting calendar

When to plant spinach in Chicago, IL - Zone 6a

Q: When is the first frost in Chicago?

Chicago (ZIP 60601) has an average first fall frost around Oct 20, leaving about 178 frost-free days.

In ZIP 60601, plant spinach around Mar 28; this uses the Chicago frost station, USDA zone 6a, and spinach timing rules.

Your Chicago calendar has a 178-day estimated frost-free season. This estimate uses the representative Chicago frost station, USDA zone 6a, and spinach timing rules.

Source: chicago-ohare 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.

Reviewed by GrowZone Editorial. Calculated from the chicago-ohare frost station and USDA zone 6a, last updated 2026-06-28.

In the Chicago area, spinach timing follows the Chicago frost window, so the local ZIP date can differ from a broad zone-only calendar.

USDA zone 6a Chicago frost station University of Illinois Extension Updated 2026-06-28

Read the method

Answer first

When to start spinach seeds indoors in Chicago

In ZIP 60601, spinach is usually direct-sown around Mar 28 instead of started indoors.

Spinach is normally direct-sown in Chicago. Use around Mar 28 as the outdoor planting window for ZIP 60601.

Seed starting schedule

Spinach dates for Chicago, IL

Step	Date	How to use it
Direct Sow	March 28, 2026	Sow seed outside when the crop and soil can handle the window.

Last frost

When is the last frost in Chicago?

Chicago (ZIP 60601) has an average last spring frost around Apr 25.

First frost

When is the first frost in Chicago?

The average first fall frost is around Oct 20, giving about 178 frost-free days.

Season map

Spinach windows by month

JanFebMarAprMayJunJulAugSepOctNovDec

Direct sow

Mar 28

Harvest

May 12

Frost watch

Sep 5

Reminder workflow

Every date has a next action

Direct sow spinachMar 28

Last frost windowApr 25

First spinach harvest windowMay 12

Last spinach sowing targetSep 5

Signal	Value	Why it matters
Last frost estimate	April 25, 2026	Warm-season transplant risk starts falling after this window.
First frost estimate	October 20, 2026	Fall planting counts backward from this date.
Season length	178 days	Longer seasons can support succession crops.
Spacing	4-6 in	Airflow and root space affect yield.
Soil temperature	40 F+	Seeds and transplants stall in cold soil.

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Local data

Why this date changes by ZIP

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

University of Illinois 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 20. A conservative last sowing target is around Sep 5.