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Field Crops, Grains & OilseedsField Crop Planting Calendar for California
California farming runs on irrigation water and regional climate, so planting plans start with water supply and local conditions rather than a statewide date.
Key points
- California has no single planting calendar, so use your region and county advisor.
- Irrigation water supply often decides crop choice and timing.
- Use soil temperature and local frost data for warm and cool-season crops.
- Heat during sensitive stages shapes planting date and variety choices.
- Follow local pesticide and water rules and keep records.
Why is there no single California calendar?
California includes the Central Valley, coastal valleys, high desert and low desert, each with its own climate and crop mix. Winters are mild in many areas, and the growing season can be long, but water supply, heat and local regulations shape what and when you plant.
UC Agriculture and Natural Resources and its county farm advisors publish crop guides for local conditions. Start with your county advisor.
Marine fog, valley heat and elevation can create very different conditions within short distances. Rely on the nearest weather station and your local farm advisor. A statewide average hides how different a coastal valley is from a desert or the northern Sacramento Valley, so always ask for local figures.
What role does water supply play?
Most field crops in California depend on irrigation, so water availability and cost often decide what goes into a field and when. Water allocations can change from year to year, and local water rules and rights apply.
Check with your irrigation district and state water agencies early in the planning season. Build a calendar that works if your allocation is smaller than expected.
If water is tight, think about which crops give the best return per unit of water and which can be skipped or delayed. Ask your advisor for local information on crop water use. Groundwater rules under state law are changing in many basins, so check what applies to your wells and plan for possible limits.
- Confirm water allocation before choosing crops
- Plan for a smaller supply
- Follow local water rules
- Record water use by field
How do you time warm-season and cool-season crops?
Warm-season crops such as corn, cotton and some beans are planted after soils warm. Cool-season crops such as small grains, some forages and winter crops can be seeded in fall or winter in mild areas.
Because winters differ across the state, use soil temperature and your own frost dates instead of a statewide calendar. UC farm advisors and county offices can give local numbers.
Plant in the order your soils warm and your equipment allows, and record the soil temperature for each field. Rice, cotton, corn and other crops each have their own needs that your advisor can describe.
How does heat affect timing?
Summer heat in inland areas can stress crops during sensitive stages such as flowering. Planting date and variety maturity can be chosen to avoid the hottest periods when possible.
Watch the National Weather Service forecasts and local weather station data. Ask your farm advisor which stages are most sensitive for your crops.
Wind, humidity and night temperatures can also affect crops. Watching weather stations helps with timing for planting, irrigation and harvest. Fog and cool coastal air can slow crop development in some areas while inland valleys heat up quickly, so use a local degree-day source if your advisor recommends one.
What about double cropping and winter forage?
The long season allows double cropping in some areas, such as a winter small grain followed by a summer crop. Each crop needs water, nutrients and time, so check the economics and water supply.
Use soil tests and local recommendations for fertility. Nutrient management and water quality rules in California are enforced by regional programs, so ask your advisor what applies to you.
Winter forages and grains can use rainfall or stored water, but total water supply varies by year. Plan as if conditions may differ from last year. Winter weeds and volunteer crops can also be an issue before planting, so plan a clean seedbed and read any herbicide label carefully.
How should you handle pesticide and regulatory timing?
Pesticide use in California is regulated at the state and county level, and licensing, permits and reporting requirements apply. The label is the law, and your county agricultural commissioner can explain local requirements.
Protect pollinators by following label directions and avoiding applications when bees are active in blooming crops.
Pollinator protection rules and bee notification programs can apply to some applications in certain counties. Ask your county agricultural commissioner what applies.
What records help most?
Record planting date, soil temperature, irrigation, variety and yield by field. Add notes about water and heat events.
These records help you adapt as water and weather change from year to year.
Keep copies of required reports and permits with your planting records so you can find them quickly if you are audited.
Sources and further reading
Last reviewed: November 2026. Educational information, ranges only. Confirm timing with your county extension office.