Warszawa, Poland · 52.23°
When to plant sweetcorn in Warszawa
The Warszawa dates are calculated from the observed last spring frost — a 2016–2025 mean of 15 April — rather than from a latitude estimate or a national calendar. The frost-free season here averages 211 days.
Season anchorobserved 2016–2025
Last spring frost: 15 April · latest 11 May
First autumn frost: 12 November · earliest 21 Oct
Frost-free season: 211 days · 10 complete years
These come from the ERA5 reanalysis on a roughly 9 km grid, so they describe the area rather than your plot. A hollow, a frost pocket or an exposed site regularly runs several degrees colder, so use the cautious date for a decision you cannot undo.
Frost date estimator →Local calendar windows
The cautious column is calculated from the latest frost recorded in the period (11 May). Use it for tender crops you cannot re-sow.
The year in Warszawa
What can move the date
Wind-pollinated: plant in a block of at least four by four, never a single long row, or the cobs come out half-empty. Never grow two varieties near each other.
Final spacing: 35 × 45 cm. Soil: pH 6–7.
Direct-sow only once the soil holds 12°C or more — soil temperature decides germination, not the date.
Problems in Warszawa
Each has its locally favourable conditions counted month by month, from the weather archive for this city.
Full guide: sweetcorn diseases and pests →