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ZIP 80903 planting calendar

When to plant lettuce in Colorado Springs, CO - Zone 6a

In ZIP 80903, plant lettuce around May 1; this uses the Colorado Springs frost station, USDA zone 6a, and lettuce timing rules.

Your Colorado Springs calendar has a 139-day estimated frost-free season. This estimate uses the representative Colorado Springs frost station, USDA zone 6a, and lettuce timing rules.

Source: colorado-springs-muni 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 Colorado Springs frost station Colorado State University Extension Updated 2026-06-28
Read the method

Answer first

When to start lettuce seeds indoors in Colorado Springs

In ZIP 80903, start lettuce seeds indoors around Apr 17, about 28 days before the May 15 last-frost estimate.

Start lettuce seeds indoors in Colorado Springs around Apr 17, about 28 days before the May 15 last-frost estimate.

Seed starting schedule

Lettuce dates for Colorado Springs, CO

StepDateHow to use it
Start IndoorsApril 17, 2026Start seeds under lights or in a bright indoor seed-starting space.
Transplant OutdoorsMay 1, 2026Move hardened-off seedlings outside after the frost-risk window.
Direct SowMay 1, 2026Sow seed outside when the crop and soil can handle the window.

Last frost

When is the last frost in Colorado Springs?

Colorado Springs (ZIP 80903) has an average last spring frost around May 15.

First frost

When is the first frost in Colorado Springs?

The average first fall frost is around Oct 1, giving about 139 frost-free days.

Season map

Lettuce windows by month

JanFebMarAprMayJunJulAugSepOctNovDec
Start indoors
Apr 17
Direct sow
May 1
Transplant
May 1
Harvest
Jun 25
Frost watch
Aug 7

Reminder workflow

Every date has a next action

Start lettuce indoorsApr 17
Direct sow lettuceMay 1
Transplant lettuceMay 1
Last frost windowMay 15
First lettuce harvest windowJun 25
Last lettuce sowing targetAug 7
SignalValueWhy it matters
Last frost estimateMay 15, 2026Warm-season transplant risk starts falling after this window.
First frost estimateOctober 1, 2026Fall planting counts backward from this date.
Season length139 daysLonger seasons can support succession crops.
Spacing8-12 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

Colorado Springs 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

Lettuce timing notes

Succession sow every 10-14 days while weather is cool. Lettuce prefers sun to part shade, 8-12 in spacing, and soil near 40 F+.

For fall, count backward from Oct 1. A conservative last sowing target is around Aug 7.