When should I plant radishes in ZIP 80903?

In ZIP 80903, the main radishes target is around Apr 17, based on the representative Colorado Springs frost station and USDA zone 6a.

When should I start radishes seeds indoors in 80903?

Radishes is usually direct-sown for ZIP 80903. Use the Apr 17 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 80903 planting calendar

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

Q: When is the first frost in Colorado Springs?

Colorado Springs (ZIP 80903) has an average first fall frost around Oct 1, leaving about 139 frost-free days.

In ZIP 80903, plant radishes around Apr 17; this uses the Colorado Springs frost station, USDA zone 6a, and radishes 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 radishes 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 radishes seeds indoors in Colorado Springs

In ZIP 80903, radishes is usually direct-sown around Apr 17 instead of started indoors.

Radishes is normally direct-sown in Colorado Springs. Use around Apr 17 as the outdoor planting window for ZIP 80903.

Seed starting schedule

Radishes dates for Colorado Springs, CO

Step	Date	How to use it
Direct Sow	April 17, 2026	Sow 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

Radishes windows by month

JanFebMarAprMayJunJulAugSepOctNovDec

Direct sow

Apr 17

Harvest

May 15

Frost watch

Sep 3

Reminder workflow

Every date has a next action

Direct sow radishesApr 17

Last frost windowMay 15

First radishes harvest windowMay 15

Last radishes sowing targetSep 3

Signal	Value	Why it matters
Last frost estimate	May 15, 2026	Warm-season transplant risk starts falling after this window.
First frost estimate	October 1, 2026	Fall planting counts backward from this date.
Season length	139 days	Longer seasons can support succession crops.
Spacing	1-2 in	Airflow and root space affect yield.
Soil temperature	40 F+	Seeds and transplants stall in cold soil.

GrowZone may earn from qualifying seed or supply links when real affiliate IDs are configured. No monetized links are active without disclosure.

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

Radishes timing notes

Fast crop; harvest promptly before roots get woody. Radishes prefers full sun, 1-2 in spacing, and soil near 40 F+.

For fall, count backward from Oct 1. A conservative last sowing target is around Sep 3.