Seed starting calculator

Your last spring frost date

Don't know your last frost date? Check your local extension office or NOAA climate normals for your area. Results update automatically once entered.

Why this matters

Timing is the single biggest lever in whether a transplant survives its first week outside. Starting too early usually means leggy, root-bound seedlings that have sat in trays too long; starting too late means a shorter season and a smaller harvest. The ranges here are deliberately wide, since a "last frost date" is a statistical average, not a guarantee — a warm spring can bring it early, and a late cold snap can still catch you off guard even after the average date has passed.

Source: Cornell University Cooperative Extension