Free garden calculator
Seed-Starting Date Calculator
Turn an editable last-spring-frost date into indoor start, direct-sow, transplant, and expected first-harvest dates.
Start indoorsMar 2, 2027
Direct-sowNot usually used
TransplantMay 4, 2027
First harvestJul 5, 2027
Use current soil conditions, the seed packet, and a short-range forecast before acting on any date.
See crop assumptions →How it works
The method
Each crop stores a reviewed frost-relative week range. Gardiv applies the typical offset to your date, then adds the crop’s typical days to maturity.
Worked example
If your average last spring frost is April 20 and a crop is normally started indoors seven weeks before frost, the planning date lands in early March.
Remember: Garden outputs are planning ranges. Weather, cultivar, soil, pests, sunlight, and care can materially change the result.
Read Gardiv’s full calculation methodology →
Common questions
Before you act on the number
Are these exact dates?
No. They are planning anchors. Soil temperature, short-term weather, seed packet directions, and plant condition still matter.
What if I buy transplants?
Use the transplant date and ignore the indoor-start task.
Is hardiness zone used?
No. Frost dates are more directly useful for annual vegetable timing.
