USDA Hardiness Zone 8b
Frost Dates for 97478 — Springfield, Oregon
Averages from Leaburg 1 Sw, Or US, the nearest reporting station, 11 miles away.
Plant tender crops after April 3, and expect the first autumn freeze around November 11. That leaves about 220 frost-free days.
- Last spring frost
- April 3
- First fall frost
- November 11
- Growing season
- 220 days
- Hardiness zone
- 8b
50% probability
50% probability
frost-free
15 to 20°F annual low
Planting calendar for 97478
| When | What to do |
|---|---|
| January 23 – February 6 | Start peppers and aubergines indoors They need eight to ten weeks under lights before they can go out. |
| February 6 – February 20 | Start tomatoes indoors Six to eight weeks gives a transplant big enough to set fruit early. |
| March 6 – March 20 | Sow peas, spinach, lettuce, radish outdoors These tolerate light frost and prefer to germinate in cool soil. |
| April 3 onward | Transplant tomatoes, peppers, basil, squash, cucumbers The average last freeze has passed — still watch the actual forecast. |
| by August 19 | Sow the autumn crop of carrots, beets and brassicas They need about twelve weeks to size up before growth stops. |
| by October 28 | Harvest tender crops, or be ready to cover them A first freeze two weeks early is well within normal variation. |
| November 11 onward | Plant garlic, mulch beds, lift tender bulbs Garlic wants a cold spell; bare soil loses structure over winter. |
What these dates mean
Wait until after April 3 to put tender plants — tomatoes, peppers, basil, squash — in the ground. That is the date by which half of years in Springfield, Oregon are past their last freeze. Harvest before November 11, which leaves roughly 220 frost-free days.
ZIP 97478 sits in USDA hardiness zone 8b, meaning the average coldest night of the year falls between 15 to 20°F. Zone decides what survives the winter; frost dates decide when to plant each spring. They are different questions, and a plant can pass one and fail the other.
These are thirty-year NOAA averages for 1991–2020, not a forecast. Any individual year can frost two to three weeks either side of these dates, so check the actual forecast before planting out.