GreenlyPortland: frost dates
United States
In Portland the last spring frost usually comes around 26 March and the first autumn frost around 22 November, which leaves about 241 frost-free days (median of 2016–2025). Tomato seedlings can go into open ground around 15 May.
| Last spring frost | around 26 March |
|---|---|
| First autumn frost | around 22 November |
| Frost-free days | 241 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 | 14 February | 26 March | 16 April |
| Arugula | — | 12 February | sow 5 March |
| Basil | 19 April | 27 May | 17 June |
| Beet | — | 12 February | sow 5 March |
| Bell Pepper | 14 March | 27 May | 17 June |
| Black-eyed Susan | 13 February | — | 16 April |
| Bok Choy | 19 February | 26 March | 16 April |
| Broad bean | — | 12 February | sow 5 March |
| Broccoli | — | 12 February | sow 5 March |
| Brussels Sprouts | 29 December | 12 February | 5 March |
| Cabbage | — | 12 February | sow 5 March |
| Calendula | — | 12 February | sow 5 March |
| Carrot | — | — | sow 5 March |
| Cauliflower | 1 January | 12 February | 5 March |
| Celeriac | 8 January | 26 March | 16 April |
| Celery | 8 January | 26 March | 16 April |
| Celosia | 16 March | 30 April | 21 May |
| Chamomile | — | 12 February | sow 5 March |
| Chayote | 13 January | 11 April | 2 May |
| Chickpea | — | — | sow 5 March |
| Chili Pepper | 21 March | 3 June | 24 June |
| China aster | 5 April | 27 May | 17 June |
| Chives | — | — | sow 5 March |
| Cilantro | — | 12 February | sow 5 March |
| Corn | — | 11 April | sow 2 May |
| Cosmos | 16 March | 30 April | 21 May |
| Cucumber | 15 April | 27 May | 17 June |
| Daikon | — | 12 February | sow 5 March |
| Delphinium | 5 January | — | 5 March |
| Dill | — | 12 February | sow 5 March |
| Eggplant | 18 March | 27 May | 17 June |
| Florence fennel | 9 February | 26 March | 16 April |
| Garden sorrel | — | 12 February | sow 5 March |
| Green Beans | 5 March | 11 April | 2 May |
| Hyssop | — | — | sow 5 March |
| Kale | — | 12 February | sow 5 March |
| Kiwano | 23 March | 24 April | 15 May |
| Kohlrabi | — | 12 February | sow 5 March |
| Leek | 4 December | 12 February | 5 March |
| Lemon balm | — | 12 February | sow 5 March |
| Lettuce | — | 12 February | sow 5 March |
| Lisianthus | 17 November | 12 February | 5 March |
| Lovage | — | — | sow 5 March |
| Luffa | 15 April | 27 May | 17 June |
| Marigold | 12 February | 26 March | 16 April |
| Melon | 5 April | 27 May | 17 June |
| Microgreens | — | 30 April | sow 21 May |
| Moringa | 9 April | 3 June | 24 June |
| Mustard greens | — | 12 February | sow 5 March |
| Napa cabbage | 21 February | 26 March | 16 April |
| Nasturtium | 16 February | 26 March | 16 April |
| Okra | 15 April | 27 May | 17 June |
| Oregano | 14 December | 12 February | 5 March |
| Pansy | 18 December | 12 February | 5 March |
| Parsley | — | 12 February | sow 5 March |
| Parsnip | — | — | sow 5 March |
| Peanut | 20 April | 27 May | 17 June |
| Peas | — | 12 February | sow 5 March |
| Petunia | 25 March | 27 May | 17 June |
| Physalis | 10 March | 24 April | 15 May |
| Pumpkin | 18 March | 24 April | 15 May |
| Purple coneflower | 2 January | — | 5 March |
| Radish | — | — | sow 5 March |
| Sage | 25 December | 12 February | 5 March |
| Snapdragon | 9 December | 12 February | 5 March |
| Spinach | — | 12 February | sow 5 March |
| Stevia | 6 March | 24 April | 15 May |
| Stock | — | 12 February | sow 5 March |
| Sunflower | — | 30 April | sow 21 May |
| Sweet Corn | — | 11 April | sow 2 May |
| Sweet pea | 1 January | 12 February | 5 March |
| Sweet William | — | — | sow 5 March |
| Swiss Chard | — | 12 February | sow 5 March |
| Thyme | — | 12 February | sow 5 March |
| Tomato | 26 February | 24 April | 15 May |
| Turnip | — | 12 February | sow 5 March |
| Watercress | — | 12 February | sow 5 March |
| Watermelon | 25 April | 27 May | 17 June |
| Zinnia | 29 April | 3 June | 24 June |
| Zucchini | 23 March | 24 April | 15 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.
Portland: 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 | 23 October |
| Crocus | 23 October |
| Daffodil | 23 October |
| Garlic | 23 October |
| Hyacinth | 23 October |
| Lily | 23 October |
| Peony | 23 October |
| Saffron | 23 October |
| Tulip | 23 October |
| Wild garlic | 23 October |
A month before the first autumn frost, so the roots grow before winter.