Frost-Zone Seed-Starting Calculator
Enter your average last spring frost — or approximate it from your USDA zone — and pick a crop to get concrete seed-starting, transplant, and direct-sow dates.
Zones set an approximate last-frost date. For accuracy, enter your own date on the right.
Use a date from a nearby weather station or extension office when you can.
Frost-tender: this crop is damaged by frost, so it goes out after the last frost date.
USDA zones describe average winter minimum temperature, not frost dates, so zone-based dates are approximate. Your local last-frost date is always more reliable. Timing also varies with weather each year.
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How it works
Seed packets give timing relative to your last frost; this tool turns that into calendar dates.
- 1Set your average last spring frost date — pick it directly, or choose your USDA zone to auto-fill an approximate date.
- 2Choose a crop. Each has conventional timing based on its frost tolerance.
- 3The tool counts back to when you should start seeds indoors, and forward to when it is safe to transplant or direct-sow.
- 4Hardy crops can go out before the last frost; frost-tender crops (like tomatoes and peppers) wait until after it.