Seed Starting Date Calculator
Get personalized seed starting dates based on your last frost date. Know exactly when to start indoors, transplant, and direct sow.
Default: April 15. Find your frost date →
| Crop | Type | Start Indoors | Transplant / Sow | Weeks |
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How It Works
This calculator works backwards from your last spring frost date to determine the ideal dates for starting seeds indoors and planting outdoors. Different crops need different lead times — some need 10-12 weeks of indoor growth, while others prefer to be sown directly in the garden.
Indoor vs. Direct Sow
Start indoors: Crops with long growing seasons (tomatoes, peppers, onions) or those that need warmth to germinate. Give them a head start under grow lights 6-12 weeks before your last frost.
Direct sow: Crops that hate transplanting (carrots, radishes, beans, corn) or grow quickly enough that indoor starting isn't needed. Root crops in particular should always be direct sown.
Hardening Off
Before transplanting indoor seedlings outdoors, harden them off over 7-10 days: gradually increase outdoor exposure from 1 hour to full days. This prevents transplant shock and sunburn.