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Field Crops, Grains & OilseedsField Crop Planting Calendar for the Pacific Northwest
The Pacific Northwest covers wet coastal valleys, dry inland plateaus and irrigated basins, so a single calendar does not fit and your own rainfall and water supply set the plan.
Key points
- Pacific Northwest planting depends on rainfall zone, irrigation and soils.
- Winter wheat seeding often depends on fall soil moisture.
- Spring crops go in when fields are fit and soils are warm enough.
- Irrigation scheduling follows soil moisture, crop stage and local water rules.
- Records help you adapt to wet and dry years.
Why does the Pacific Northwest need separate calendars?
West of the Cascades, winters are mild and wet and summers are dry. East of the Cascades, rainfall drops, winters are colder and many fields are either dryland or irrigated from rivers and wells. Crop choices and planting dates differ across these zones.
Washington State, Oregon State and University of Idaho Extension each publish crop information for their regions. Start with the guide nearest your county.
Elevation also matters. Higher-elevation areas have shorter seasons and later last spring frosts than valley bottoms, even within the same county.
How does fall-seeded wheat fit?
In much of the inland Northwest, winter wheat is a major crop. Seeding date depends on soil moisture and the need for seedlings to establish before winter. In dry areas, farmers may seed into stored soil moisture, and timing may depend on fall rains.
Ask your extension office for recommended seeding windows in your rainfall zone, and plan for what happens if fall rain is late.
Seeding too early can lead to excess fall growth that is exposed to winter damage or pests, and seeding too late leaves less time to tiller. Ask your extension office where the balance falls in your rainfall zone. A late fall can also mean wheat seeded into dry soil sits ungerminated until rain arrives, so some growers keep records of how long seed waited in past years.
- Check stored soil moisture before seeding
- Match seeding date to your rainfall zone
- Plan for late fall rain
- Confirm variety recommendations locally
When do spring crops go in?
Spring wheat, barley, peas, lentils, canola and other spring crops are seeded as soon as fields are fit and soils are warm enough. Cool soils slow emergence, while late seeding exposes crops to summer heat and dry weather.
Use your frost dates and the forecast, and confirm the recommended range for each crop with your extension office.
Pulse crops, canola and other spring crops each have specific planting guidance from WSU, Oregon State and the University of Idaho. Use the crop-specific publication for each. Frost can occur late in higher areas, so check the forecast for sensitive crops like peas and canola in flower.
How does irrigation change the calendar?
Irrigated areas can grow warm-season crops such as corn, potatoes and beans, and water supply becomes a key planning item. Scheduling should follow soil moisture and crop stage, and local water rules and rights apply.
Check with your irrigation district and state water agency before you plan. The U.S. Drought Monitor shows current conditions.
If you irrigate from a river or canal, the timing of when water becomes available can be a bigger constraint than soil temperature, so confirm your water delivery dates early.
What about wet springs west of the Cascades?
In the wetter valleys, spring planting often depends on when fields drain. Heavy soils may stay wet well into the season, delaying fieldwork. Grass seed, vegetables and small grains have different timing needs.
Avoid working wet soil, as compaction can persist. Your extension office can explain local recommendations.
Grass seed, vegetable seed and other specialty crops are widely grown in the Willamette Valley and nearby areas, and the timing of those crops can influence field availability for others. Drainage tile, ditches and field slope all change how soon fields can be worked, so mark wet spots on a map and plan around them.
How do you plan cover crops and rotation?
Rotations that include small grains, legumes and other crops are common in the region, and cover crops can fit where moisture allows. Moisture is often the limiting factor in dryland systems.
Ask extension and NRCS about options. Soil tests and local recommendations should guide fertility, and nutrient management rules vary by state.
Cover crops that grow in fall and spring in wetter areas may need to be terminated earlier to let soils dry and warm before planting. Ask your conservation district for local advice.
What records help you refine the plan?
Note seeding date, soil moisture, emergence, weather and yield by field. Add notes about fall rain timing.
These records will show you how your fields respond in wet and dry years.
A weather station log, even a simple rain gauge by the field, adds useful local data to your yearly records. Take photos of fields in early spring each year to show how winter treated them.
Sources and further reading
Last reviewed: November 2026. Educational information, ranges only. Confirm timing with your county extension office.