Warm-Season Vegetable

When to Plant Tomatoes in Oregon

America's favorite garden vegetable (technically a fruit). Nothing beats a sun-warmed tomato straight off the vine.

The Short Answer

In Oregon, tomatoes planting dates vary by region. In Willamette Valley, your average last frost is around Mar 25 - Apr 15, while Southern Oregon Coast sees its last frost around Mar 5 - Mar 25. Since tomatoes are frost-sensitive, start seeds indoors 6 weeks before your last frost, then transplant outside 2 weeks after frost danger has passed. Rich volcanic soils in Willamette Valley. Dry, alkaline soils east of Cascades. Acidic forest soils on coast. Generally...

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

Tomatoes Planting Schedule for Oregon

Willamette Valley (Zones 8a, 8b)

Average last frost: Mar 25 - Apr 15 · Average first frost: Oct 15 - Nov 10

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks after frost
Direct Sow
2 wks after frost

Portland Metro (Zones 8b, 9a)

Average last frost: Mar 15 - Apr 5 · Average first frost: Oct 25 - Nov 15

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks after frost
Direct Sow
2 wks after frost

Central/Eastern Oregon (Zones 5a, 5b, 6a, 6b)

Average last frost: May 10 - Jun 1 · Average first frost: Sep 10 - Oct 1

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks after frost
Direct Sow
2 wks after frost

Southern Oregon Coast (Zones 8b, 9a, 9b)

Average last frost: Mar 5 - Mar 25 · Average first frost: Nov 5 - Nov 25

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks after frost
Direct Sow
2 wks after frost

Growing Tomatoes in Oregon

Tomatoes in Oregon's Climate

Your long growing season gives tomatoes plenty of time, but extreme summer heat above 95°F can cause blossom drop and pause fruit set during the hottest weeks. In the Deep South and Texas, many growers aim for two tomato seasons — spring (transplant early) and fall (start new plants in July). Choose heat-tolerant varieties like Heat Wave, Solar Fire, and Phoenix. Afternoon shade from taller plants can help during the most brutal July-August heat.

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 60°F before planting tomatoes 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. Tomatoes 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 tomatoes — transplant timing shifts by several weeks across the state.

Growing Tips

Pinch off suckers for indeterminate varieties. Stake or cage for best results. Water at the base, not overhead, to prevent blight.

Companion Planting

Plant tomatoes alongside these companions for better growth:

Basil Carrots Peppers Marigolds

Keep tomatoes away from:

Brassicas Fennel Dill

The Bottom Line

Tomatoes can be grown successfully across Oregon, but your exact planting dates depend on which region you're in. Willamette Valley gardeners should plan around a Mar 25 - Apr 15 last frost, while those in Southern Oregon Coast can typically plant earlier. For exact dates based on your zip code, use our free planting date finder.
Note: All dates are based on NOAA 30-year Climate Normals and represent historical averages, not predictions for any specific year. Always check your local weather forecast before planting frost-sensitive crops. Learn about our data sources.

Last reviewed: March 29, 2026

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