GreenlyPhoenix: frost dates
United States
In Phoenix the last spring frost usually comes around 4 February and the first autumn frost around 29 December, which leaves about 328 frost-free days (median of 2016–2025). Tomato seedlings can go into open ground around 11 February.
| Last spring frost | around 4 February |
|---|---|
| First autumn frost | around 29 December |
| Frost-free days | 328 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 | 12 December | 21 January | 11 February |
| Arugula | — | 24 December | sow 14 January |
| Basil | 26 December | 2 February | 23 February |
| Beet | — | 24 December | sow 14 January |
| Bell Pepper | 20 November | 2 February | 23 February |
| Black-eyed Susan | 11 December | — | 11 February |
| Bok Choy | 17 December | 21 January | 11 February |
| Broad bean | — | 24 December | sow 14 January |
| Broccoli | — | 24 December | sow 14 January |
| Brussels Sprouts | 9 November | 24 December | 14 January |
| Cabbage | — | 24 December | sow 14 January |
| Calendula | — | 24 December | sow 14 January |
| Carrot | — | — | sow 14 January |
| Cauliflower | 12 November | 24 December | 14 January |
| Celeriac | 5 November | 21 January | 11 February |
| Celery | 5 November | 21 January | 11 February |
| Celosia | 7 December | 21 January | 11 February |
| Chamomile | — | 24 December | sow 14 January |
| Chayote | 25 October | 21 January | 11 February |
| Chickpea | — | — | sow 14 January |
| Chili Pepper | 6 December | 18 February | 11 March |
| China aster | 12 December | 2 February | 23 February |
| Chives | — | — | sow 14 January |
| Cilantro | — | 24 December | sow 14 January |
| Corn | — | 21 January | sow 11 February |
| Cosmos | 7 December | 21 January | 11 February |
| Cucumber | 22 December | 2 February | 23 February |
| Daikon | — | 24 December | sow 14 January |
| Delphinium | 16 November | — | 14 January |
| Dill | — | 24 December | sow 14 January |
| Eggplant | 24 November | 2 February | 23 February |
| Florence fennel | 7 December | 21 January | 11 February |
| Garden sorrel | — | 24 December | sow 14 January |
| Green Beans | 15 December | 21 January | 11 February |
| Hyssop | — | — | sow 14 January |
| Kale | — | 24 December | sow 14 January |
| Kiwano | 20 December | 21 January | 11 February |
| Kohlrabi | — | 24 December | sow 14 January |
| Leek | 15 October | 24 December | 14 January |
| Lemon balm | — | 24 December | sow 14 January |
| Lettuce | — | 24 December | sow 14 January |
| Lisianthus | 28 September | 24 December | 14 January |
| Lovage | — | — | sow 14 January |
| Luffa | 22 December | 2 February | 23 February |
| Marigold | 10 December | 21 January | 11 February |
| Melon | 12 December | 2 February | 23 February |
| Microgreens | — | 21 January | sow 11 February |
| Moringa | 25 December | 18 February | 11 March |
| Mustard greens | — | 24 December | sow 14 January |
| Napa cabbage | 19 December | 21 January | 11 February |
| Nasturtium | 14 December | 21 January | 11 February |
| Okra | 22 December | 2 February | 23 February |
| Oregano | 25 October | 24 December | 14 January |
| Pansy | 29 October | 24 December | 14 January |
| Parsley | — | 24 December | sow 14 January |
| Parsnip | — | — | sow 14 January |
| Peanut | 27 December | 2 February | 23 February |
| Peas | — | 24 December | sow 14 January |
| Petunia | 1 December | 2 February | 23 February |
| Physalis | 7 December | 21 January | 11 February |
| Pumpkin | 15 December | 21 January | 11 February |
| Purple coneflower | 13 November | — | 14 January |
| Radish | — | — | sow 14 January |
| Sage | 5 November | 24 December | 14 January |
| Snapdragon | 20 October | 24 December | 14 January |
| Spinach | — | 24 December | sow 14 January |
| Stevia | 3 December | 21 January | 11 February |
| Stock | — | 24 December | sow 14 January |
| Sunflower | — | 21 January | sow 11 February |
| Sweet Corn | — | 21 January | sow 11 February |
| Sweet pea | 12 November | 24 December | 14 January |
| Sweet William | — | — | sow 14 January |
| Swiss Chard | — | 24 December | sow 14 January |
| Thyme | — | 24 December | sow 14 January |
| Tomato | 25 November | 21 January | 11 February |
| Turnip | — | 24 December | sow 14 January |
| Watercress | — | 24 December | sow 14 January |
| Watermelon | 1 January | 2 February | 23 February |
| Zinnia | 14 January | 18 February | 11 March |
| Zucchini | 20 December | 21 January | 11 February |
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.
Phoenix: 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 | 29 November |
| Crocus | 29 November |
| Daffodil | 29 November |
| Garlic | 29 November |
| Hyacinth | 29 November |
| Lily | 29 November |
| Peony | 29 November |
| Saffron | 29 November |
| Tulip | 29 November |
| Wild garlic | 29 November |
A month before the first autumn frost, so the roots grow before winter.