Calculate the perfect time to start your seeds indoors
Perfect Timing for Seed Success
Starting seeds at the right time is crucial for healthy transplants and a thriving garden. Too early and seedlings become leggy and weak; too late and you miss peak growing season. This calculator takes the guesswork out of timing.
💡 Key Information: Most vegetable seedlings need 6-10 weeks of indoor growth before transplanting. Different crops have different requirements. This calculator helps you find the exact date to start seeds for your local frost date.
🌱 Calculate Your Seed Starting Date
✅ Your Seed Starting Schedule
Plant Type:
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📅 Start Seeds Indoors By:
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🌱 Estimated Seedling Age at Transplant:
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🌿 Transplant Outdoors By:
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📊 Days from Start to Transplant:
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⚠️ Important Notes:
- Always check your local frost date – it varies by region
- Harden off seedlings 7-10 days before transplanting
- Keep seedlings under grow lights for 14-16 hours daily
- Maintain soil temperature of 70-75°F for best germination
📖 Seed Starting Guide
Here’s a comprehensive table of common vegetables and herbs with their typical seed-starting requirements:
| Plant | Weeks Before Frost | Soil Temperature | Days to Germinate | Light Required |
|---|---|---|---|---|
| Tomatoes | 6-8 weeks | 70-80°F | 5-10 days | 14-16 hours |
| Peppers | 8-10 weeks | 70-85°F | 7-14 days | 14-16 hours |
| Eggplant | 8-10 weeks | 70-85°F | 7-14 days | 14-16 hours |
| Cabbage | 5-7 weeks | 65-75°F | 5-10 days | 14-16 hours |
| Broccoli | 4-6 weeks | 65-75°F | 5-10 days | 14-16 hours |
| Lettuce | 3-4 weeks | 60-70°F | 7-10 days | 12-14 hours |
| Basil | 5-7 weeks | 70-75°F | 5-10 days | 14-16 hours |
| Cucumber | 2-3 weeks | 70-80°F | 3-10 days | 14-16 hours |
| Squash | 3-4 weeks | 70-80°F | 7-10 days | 14-16 hours |
| Melon | 3-4 weeks | 75-85°F | 7-10 days | 14-16 hours |
🌱 Seed Starting Success Tips
Optimal Growing Conditions
- Lighting: 14-16 hours of bright light daily (grow lights work great)
- Temperature: 70-75°F during day, 60-65°F at night
- Moisture: Keep soil consistently moist but not waterlogged
- Air Circulation: Use a small fan to strengthen seedling stems
- Humidity: 60-70% is ideal (use a humidity dome initially)
Common Problems & Solutions
- Leggy Seedlings: Not enough light – move closer to grow lights
- Damping Off: Fungal disease – ensure good air circulation and proper watering
- Slow Growth: Too cold – increase temperature to optimal range
- Yellow Leaves: Nitrogen deficiency – fertilize with dilute liquid fertilizer
- Wilting: Overwatering – allow soil to dry slightly between waterings
Hardening Off Seedlings
Before transplanting outdoors, gradually expose seedlings to outdoor conditions over 7-10 days:
- Day 1-2: Place in shade for 2-3 hours
- Day 3-4: 4-5 hours in dappled light
- Day 5-6: 6-8 hours with some direct sun
- Day 7-8: Full day outside, bring in at night
- Day 9+: Leave outside overnight if temps stay above 50°F
Fertilizing Seedlings
- Start fertilizing after true leaves appear (not cotyledons)
- Use diluted liquid fertilizer (half-strength) every 7-10 days
- A balanced fertilizer (10-10-10) works well for most seedlings
- Never fertilize dry soil – water first