How the result is calculated
Indoor sowing date = average last frost date minus the selected number of weeks.
SproutScale preserves full precision while calculating and rounds only the displayed result or the final purchasable unit.
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Seed Starting Date Calculator
Convert packet guidance such as “start 6–8 weeks before last frost” into a calendar date.
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calculationNo garden data uploaded
calculationNo garden data uploaded
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Updates liveEnter your measurements
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Planning result
Start seeds indoorsFebruary 18, 2027
Lead time8 weeks
Days before frost56 days
Frost date usedApril 15, 2027
Use this as a planning estimate. Verify product labels, local conditions and supplier packaging before buying or applying materials.
Before you act
- Use a local average frost date, not a guarantee.
- Adjust for crop hardiness and transplant age.
- Plan a hardening-off period before outdoor transplanting.
Seed starting date FAQ
Why is an average frost date uncertain?
It is based on historical probability; a late cold event can still occur, so monitor the forecast.
Should every seed be started indoors?
No. Root crops and many fast crops are usually better direct-sown according to packet guidance.