Plan a sowing and harvest day from days to maturity.
Seedlings started indoors are moved out around the frost date, so the sowing day backs up from frost by the start lead time. Back-counting from frost and maturity keeps transplants ready on time, which is the difference between a full and a wasted season.
Sowing Date
Sow day = last frost - sow-before; harvest = sow day + days to maturity
Sow day = last frost - sow-before; harvest = sow day + days to maturity Seedlings started indoors are moved out around the frost date, so the sowing day backs up from frost by the start lead time.
Back-counting from frost and maturity keeps transplants ready on time, which is the difference between a full and a wasted season.
This calculator takes 3 inputs: Last frost day of year, Days to maturity, Sow days before frost. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.