When should I plant cucumbers in ZIP 80012?

In ZIP 80012, the main cucumbers target is around May 15, based on the representative Denver frost station and USDA zone 6a.

When should I start cucumbers seeds indoors in 80012?

Start cucumbers seeds indoors in ZIP 80012 around Apr 14, about 21 days before the May 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 80012 planting calendar

When to plant cucumbers 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 cucumbers around May 15; this uses the Denver frost station, USDA zone 6a, and cucumbers 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 cucumbers 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 cucumbers seeds indoors in Aurora

In ZIP 80012, start cucumbers seeds indoors around Apr 14, about 21 days before the May 5 last-frost estimate.

Start cucumbers seeds indoors in Aurora around Apr 14, about 21 days before the May 5 last-frost estimate.

Seed starting schedule

Cucumbers dates for Aurora, CO

Step	Date	How to use it
Start Indoors	April 14, 2026	Start seeds under lights or in a bright indoor seed-starting space.
Transplant Outdoors	May 15, 2026	Move hardened-off seedlings outside after the frost-risk window.
Direct Sow	May 15, 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

Cucumbers windows by month

JanFebMarAprMayJunJulAugSepOctNovDec

Start indoors

Apr 14

Direct sow

May 15

Transplant

May 15

Harvest

Jul 14

Frost watch

Aug 6

Reminder workflow

Every date has a next action

Start cucumbers indoorsApr 14

Last frost windowMay 5

Direct sow cucumbersMay 15

Transplant cucumbersMay 15

First cucumbers harvest windowJul 14

Last cucumbers sowing targetAug 6

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	12-18 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

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

Cucumbers timing notes

Use a trellis if space is tight and keep soil evenly moist. Cucumbers prefers full sun, 12-18 in spacing, and soil near 65 F+.

For fall, count backward from Oct 5. A conservative last sowing target is around Aug 6.