When to Plant Pumpkins in Oregon
From jack-o-lanterns to pies, pumpkins need space and time but deliver a uniquely satisfying harvest.
The Short Answer
Oregon Frost Dates
Your planting dates depend on which part of Oregon you're in. Here are the frost date ranges by region:
| Region | Zones | Last Frost (Spring) | First Frost (Fall) |
|---|---|---|---|
| Willamette Valley | 8a, 8b | Mar 25 - Apr 15 | Oct 15 - Nov 10 |
| Portland Metro | 8b, 9a | Mar 15 - Apr 5 | Oct 25 - Nov 15 |
| Central/Eastern Oregon | 5a, 5b, 6a, 6b | May 10 - Jun 1 | Sep 10 - Oct 1 |
| Southern Oregon Coast | 8b, 9a, 9b | Mar 5 - Mar 25 | Nov 5 - Nov 25 |
Pumpkins Planting Schedule for Oregon
Willamette Valley (Zones 8a, 8b)
Average last frost: Mar 25 - Apr 15 · Average first frost: Oct 15 - Nov 10
Portland Metro (Zones 8b, 9a)
Average last frost: Mar 15 - Apr 5 · Average first frost: Oct 25 - Nov 15
Central/Eastern Oregon (Zones 5a, 5b, 6a, 6b)
Average last frost: May 10 - Jun 1 · Average first frost: Sep 10 - Oct 1
Southern Oregon Coast (Zones 8b, 9a, 9b)
Average last frost: Mar 5 - Mar 25 · Average first frost: Nov 5 - Nov 25
Growing Pumpkins in Oregon
Pumpkins in Oregon's Climate
Your long season means you can plant pumpkins later than northern growers while still getting October harvest. The trick is timing: plant in June-July so pollination occurs in September when temperatures have moderated from peak summer heat. Squash vine borer often has two generations in warm climates — the later planting helps avoid the worst damage.
Soil Considerations for Oregon
Rich volcanic soils in Willamette Valley. Dry, alkaline soils east of Cascades. Acidic forest soils on coast. Generally excellent for gardening in valleys. Make sure soil has warmed to at least 65°F before planting pumpkins outside.
Oregon Climate & Growing Season
Dramatic east-west climate divide. Wet, mild winters west of Cascades. Dry, cold winters east. Year-round gardening possible in mild western valleys. Pumpkins cannot tolerate any frost, so wait until all frost danger has passed before transplanting outside. Watch local forecasts carefully in spring.
Growing season length varies across Oregon: Willamette Valley (8a, 8b) has a last frost around Mar 25 - Apr 15, while Southern Oregon Coast (8b, 9a, 9b) sees frost end around Mar 5 - Mar 25. This difference matters for pumpkins — transplant timing shifts by several weeks across the state.
Growing Tips
Count backwards from when you want ripe pumpkins (usually October). They need 90-120 days, so mid-June to early July is often ideal.
Companion Planting
Plant pumpkins alongside these companions for better growth:
Keep pumpkins away from:
The Bottom Line
Last reviewed: March 29, 2026