When to Start Tomato Seeds Indoors for April 15 Last Frost?
With a last frost of April 15 and 8 weeks before transplant, you should start tomato seeds indoors around February 18.
How to use this tool
- Enter your average last spring frost date.
- Enter the number of weeks before transplanting to start seeds indoors (from the seed packet).
- The calculator returns the date you should sow seeds indoors.
Zone 5 gardeners with an April 15 last frost date should start tomatoes indoors 8 weeks earlier, in mid-February.
Frequently asked questions
- When should I start seeds indoors?
- Most vegetables should be started 6–10 weeks before your last frost date. Tomatoes and peppers need 8–10 weeks; broccoli and cabbage need 4–6 weeks. Always check the seed packet.
- How do I find my last frost date?
- Enter your zip code on the USDA Plant Hardiness Zone Map website or ask your local cooperative extension service for the average last frost date in your area.