State agricultural overview
Idaho crop calendar.
Zone 5bRange 3b to 7a130-day seasonLast frost May 15First frost September 25
16 primary crops with planting windows for Idaho. Calendar timing is anchored to 5b dominant hardiness zone and a 130-day growing season — verify against University of Idaho Extension for variety- and county-specific guidance.
Row Crop · Idaho
- CornprimarySpring: May 15 – June 5
- SoybeansprimarySpring: May 29 – June 19
- SunflowersprimarySpring: May 22 – June 19
- Winter WheatprimaryFall: September 18 – October 9
- Grain SorghumsecondarySpring: June 5 – July 3
- CottontrialSpring: May 29 – June 19
Cover Crops · Idaho
- BrassicasprimaryFall: July 12 – July 27
- BuckwheatprimarySpring: July 10 – August 7
- Cereal OatsprimarySpring: May 8 – June 5Fall: July 27 – August 11
- Winter RyeprimaryFall: September 18 – October 9
Frost-date reference — Idaho
Last frost (spring)
May 15
First frost (fall)
September 25
Growing season
130 days
Hardiness zone
5b
Frost dates are NOAA / NCDC climate normals — county-level variation can shift these by 2–4 weeks. The Idaho extension service publishes county-specific frost data: University of Idaho Extension.
Idaho soil-temp alerts.
Bield: Farm ties weather and soil-temperature stations in your county to crop planting thresholds — get notified the day soil temp clears the threshold for your target.