GrowZone

Seed-start answer

Start tomatoes seeds indoors around Apr 3

In ZIP 80903, start tomatoes seeds indoors around Apr 3, about 42 days before the May 15 last-frost estimate.

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.

This uses ZIP 80903, the Colorado Springs frost station, and the May 15 last-frost estimate.

Seed starting schedule

Tomatoes dates for Colorado Springs, CO

StepDateHow to use it
Start IndoorsApril 3, 2026Start seeds under lights or in a bright indoor seed-starting space.
Transplant OutdoorsMay 22, 2026Move hardened-off seedlings outside after the frost-risk window.