GreenlyWhen to plant watermelon in Prague
In Prague, watermelon: sow seedlings around 11 April for the greenhouse and around 2 May for open ground; plant into a greenhouse around 13 May; plant out into open ground around 3 June.
Last spring frost around 20 April, first autumn frost around 8 November. Frost-free days: 202 days.
The dates follow the Greenly calendar: open ground a week after the last frost once the soil is warm enough for the crop, frost-hardy crops three weeks before it, an unheated greenhouse three weeks earlier, seedlings sown so they are ready on the day. In a cold year allow a week or two more.