GreenlyLondon: frost dates
United Kingdom
| Last spring frost | around 4 April |
|---|---|
| First autumn frost | around 23 November |
| Frost-free days | 233 days |
Median of 2016–2025 for the 25 km grid cell of the city: the last day at or below 0 °C in spring and the first in autumn (ERA5 reanalysis via Open-Meteo). In a cold year a frost can come a week or two later — Greenly warns 48 hours ahead.
When to sow and plant
| Crop | Sow for seedlings | Plant out in a greenhouse | Open ground |
|---|---|---|---|
| Bell Pepper | 9 March | 22 May | 12 June |
| Chili Pepper | 25 March | 7 June | 28 June |
| Corn | — | 31 March | sow 21 April |
| Cucumber | 10 April | 22 May | 12 June |
| Eggplant | 13 March | 22 May | 12 June |
| Green Beans | 22 February | 31 March | 21 April |
| Melon | 31 March | 22 May | 12 June |
| Peas | — | 21 February | sow 14 March |
| Physalis | 19 March | 3 May | 24 May |
| Pumpkin | 27 March | 3 May | 24 May |
| Sweet Corn | — | 31 March | sow 21 April |
| Tomato | 7 March | 3 May | 24 May |
| Watermelon | 20 April | 22 May | 12 June |
| Zucchini | 1 April | 3 May | 24 May |
Planting out: 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 are sown so they are ready on that day.
Planted in autumn
| Crop | Plant around |
|---|---|
| Crocus | 24 October |
| Daffodil | 24 October |
| Garlic | 24 October |
| Hyacinth | 24 October |
| Lily | 24 October |
| Tulip | 24 October |
A month before the first autumn frost, so the roots grow before winter.