When should I plant spinach in ZIP 80012?

In ZIP 80012, the main spinach target is around Apr 7, based on the representative Denver frost station and USDA zone 6a.

When should I start spinach seeds indoors in 80012?

Spinach is usually direct-sown for ZIP 80012. Use the Apr 7 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 80012 planting calendar

When to plant spinach in Aurora, CO - Zone 6a

Q: When is the first frost in Aurora?

Aurora (ZIP 80012) has an average first fall frost around Oct 5, leaving about 153 frost-free days.

In ZIP 80012, plant spinach around Apr 7; this uses the Denver frost station, USDA zone 6a, and spinach timing rules.

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

Source: denver-intl 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 Denver frost station Colorado State University Extension Updated 2026-06-28

Read the method

Answer first

When to start spinach seeds indoors in Aurora

In ZIP 80012, spinach is usually direct-sown around Apr 7 instead of started indoors.

Spinach is normally direct-sown in Aurora. Use around Apr 7 as the outdoor planting window for ZIP 80012.

Seed starting schedule

Spinach dates for Aurora, CO

Step	Date	How to use it
Direct Sow	April 7, 2026	Sow seed outside when the crop and soil can handle the window.

Last frost

When is the last frost in Aurora?

Aurora (ZIP 80012) has an average last spring frost around May 5.

First frost

When is the first frost in Aurora?

The average first fall frost is around Oct 5, giving about 153 frost-free days.

Season map

Spinach windows by month

JanFebMarAprMayJunJulAugSepOctNovDec

Direct sow

Apr 7

Harvest

May 22

Frost watch

Aug 21

Reminder workflow

Every date has a next action

Direct sow spinachApr 7

Last frost windowMay 5

First spinach harvest windowMay 22

Last spinach sowing targetAug 21

Signal	Value	Why it matters
Last frost estimate	May 5, 2026	Warm-season transplant risk starts falling after this window.
First frost estimate	October 5, 2026	Fall planting counts backward from this date.
Season length	153 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

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

Colorado 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

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 5. A conservative last sowing target is around Aug 21.