GreenlyBelfast: frost dates
United Kingdom
In Belfast the last spring frost usually comes around 18 April and the first autumn frost around 19 November, which leaves about 215 frost-free days (median of 2016–2025). Tomato seedlings can go into open ground around 15 June.
| Last spring frost | around 18 April |
|---|---|
| First autumn frost | around 19 November |
| Frost-free days | 215 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 |
|---|---|---|---|
| Achocha | 4 March | 13 April | 4 May |
| Arugula | — | 7 March | sow 28 March |
| Basil | 9 May | 16 June | 7 July |
| Beet | — | 7 March | sow 28 March |
| Bell Pepper | 3 April | 16 June | 7 July |
| Black-eyed Susan | 3 March | — | 4 May |
| Bok Choy | 9 March | 13 April | 4 May |
| Broad bean | — | 7 March | sow 28 March |
| Broccoli | — | 7 March | sow 28 March |
| Brussels Sprouts | 21 January | 7 March | 28 March |
| Cabbage | — | 7 March | sow 28 March |
| Calendula | — | 7 March | sow 28 March |
| Carrot | — | — | sow 28 March |
| Cauliflower | 24 January | 7 March | 28 March |
| Celeriac | 26 January | 13 April | 4 May |
| Celery | 26 January | 13 April | 4 May |
| Celosia | 16 April | 31 May | 21 June |
| Chamomile | — | 7 March | sow 28 March |
| Chayote | 25 January | 23 April | 14 May |
| Chickpea | — | — | sow 28 March |
| Chili Pepper | 20 April | 3 July | 24 July |
| China aster | 25 April | 16 June | 7 July |
| Chives | — | — | sow 28 March |
| Cilantro | — | 7 March | sow 28 March |
| Corn | — | 23 April | sow 14 May |
| Cosmos | 16 April | 31 May | 21 June |
| Cucumber | 5 May | 16 June | 7 July |
| Daikon | — | 7 March | sow 28 March |
| Delphinium | 28 January | — | 28 March |
| Dill | — | 7 March | sow 28 March |
| Eggplant | 7 April | 16 June | 7 July |
| Florence fennel | 27 February | 13 April | 4 May |
| Garden sorrel | — | 7 March | sow 28 March |
| Green Beans | 17 March | 23 April | 14 May |
| Hyssop | — | — | sow 28 March |
| Kale | — | 7 March | sow 28 March |
| Kiwano | 23 April | 25 May | 15 June |
| Kohlrabi | — | 7 March | sow 28 March |
| Leek | 27 December | 7 March | 28 March |
| Lemon balm | — | 7 March | sow 28 March |
| Lettuce | — | 7 March | sow 28 March |
| Lisianthus | 10 December | 7 March | 28 March |
| Lovage | — | — | sow 28 March |
| Luffa | 5 May | 16 June | 7 July |
| Marigold | 2 March | 13 April | 4 May |
| Melon | 25 April | 16 June | 7 July |
| Microgreens | — | 31 May | sow 21 June |
| Moringa | 9 May | 3 July | 24 July |
| Mustard greens | — | 7 March | sow 28 March |
| Napa cabbage | 11 March | 13 April | 4 May |
| Nasturtium | 6 March | 13 April | 4 May |
| Okra | 5 May | 16 June | 7 July |
| Oregano | 6 January | 7 March | 28 March |
| Pansy | 10 January | 7 March | 28 March |
| Parsley | — | 7 March | sow 28 March |
| Parsnip | — | — | sow 28 March |
| Peanut | 10 May | 16 June | 7 July |
| Peas | — | 7 March | sow 28 March |
| Petunia | 14 April | 16 June | 7 July |
| Physalis | 10 April | 25 May | 15 June |
| Pumpkin | 18 April | 25 May | 15 June |
| Purple coneflower | 25 January | — | 28 March |
| Radish | — | — | sow 28 March |
| Sage | 17 January | 7 March | 28 March |
| Snapdragon | 1 January | 7 March | 28 March |
| Spinach | — | 7 March | sow 28 March |
| Stevia | 6 April | 25 May | 15 June |
| Stock | — | 7 March | sow 28 March |
| Sunflower | — | 31 May | sow 21 June |
| Sweet Corn | — | 23 April | sow 14 May |
| Sweet pea | 24 January | 7 March | 28 March |
| Sweet William | — | — | sow 28 March |
| Swiss Chard | — | 7 March | sow 28 March |
| Thyme | — | 7 March | sow 28 March |
| Tomato | 29 March | 25 May | 15 June |
| Turnip | — | 7 March | sow 28 March |
| Watercress | — | 7 March | sow 28 March |
| Watermelon | 15 May | 16 June | 7 July |
| Zinnia | 29 May | 3 July | 24 July |
| Zucchini | 23 April | 25 May | 15 June |
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.
Belfast: weather for the next 7 days
Forecast by Open-Meteo. Nights at or below 0 °C are marked as frost.
Planted in autumn
| Crop | Plant around |
|---|---|
| Bearded Iris | 20 October |
| Crocus | 20 October |
| Daffodil | 20 October |
| Garlic | 20 October |
| Hyacinth | 20 October |
| Lily | 20 October |
| Peony | 20 October |
| Saffron | 20 October |
| Tulip | 20 October |
| Wild garlic | 20 October |
A month before the first autumn frost, so the roots grow before winter.