Work out frost date planting window instantly with clear inputs, formula shown and shareable results.
The frost free window is the number of days between the last spring and first autumn frost, and the latest sowing date counts the crop's maturity period back from the autumn frost. Knowing the spare days is what tells you whether a second sowing is realistic or whether the season only supports one crop of that variety.
Growing window
window = days between last spring frost and first autumn frost
Latest sowing
latest sow date = first autumn frost - days to maturity
window = days between last spring frost and first autumn frost. The frost free window is the number of days between the last spring and first autumn frost, and the latest sowing date counts the crop's maturity period back from the autumn frost.
Knowing the spare days is what tells you whether a second sowing is realistic or whether the season only supports one crop of that variety.
Enter last spring frost, first autumn frost, days to maturity for the crop. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.