Seed Starting Calculator

When should I start seeds indoors?

Crop

Start tomatoes on

Feb 25indoors

A common guide. Local weather and your seed packet come first.

StartFeb 25FrostApr 15OutdoorsApr 29
Last frostApr 15
Weeks indoors9
Move outdoors aroundApr 29

Enter your last frost date and crop to see when to sow indoors and move plants outside.

How it works

Counts back the typical indoor weeks from your last frost, then forward or back to the usual outdoor date.

Before you order

  • Use a local frost date from your extension office.
  • Harden off seedlings for about a week before planting out.
  • Starting too early creates leggy plants, so resist the urge.

Common questions

When is the last frost date?

It varies by location and is an average. Your local extension service is a reliable source.

Can I start squash and cucumbers indoors?

Yes, but keep it short since they dislike root disturbance.