Corn planting in Idaho.
Corn planting in Idaho is shaped by the state's 5b dominant hardiness zone, last frost date around May 15, and a 130-day growing season. Corn is widely grown in Idaho — commercially significant or common in home gardens and food plots.
Planting dates on this page are climatological estimates from USDA frost-date norms and zone-typical planting offsets. Verify against University of Idaho Extension for variety- and county-specific guidance.
Planting calendar — 2026
Planting windows shift earlier in southern parts of the state and later in northern parts. Use last frost date in your specific county as the reference.
Planting windows
Spring planting
CornHarvest window
Harvest timing varies with planting date and seasonal weather — these dates are typical for the ideal planting window.
Growing notes
Corn grows well in Idaho's typical climate. Idaho's 130-day growing season and 5b hardiness zone support reliable production with appropriate variety selection.
Corn is widely grown in Idaho — commercially significant or common in home gardens and food plots.
Agronomy reference
Growing-degree-day requirement: 2400 GDD (base 50°F) from planting to maturity.
Maturity varies by hybrid relative maturity (RM) — choose RM appropriate for your growing season length.
Common pests to watch
- European corn borer
- Western corn rootworm
- Corn earworm
Pest pressure varies by region and year. Confirm current outbreaks with University of Idaho Extension.
Common diseases
- Gray leaf spot
- Northern corn leaf blight
- Tar spot
Resistance varieties shift each year. Check the current variety trial report for your state.
Variety selection
Corn varieties for Idaho live with your extension service.
Variety performance is micro-regional and changes with each year’s trial cycle. We don’t republish variety lists — instead, we point directly at the source.
Search the extension site for “cornvariety trial” or “recommended corn varieties” to find the current report.
Yield varies significantly by variety, soil, fertility, and management. Consult your state extension service for variety performance trials in your region.
Beyond the harvest
Corn as a hunting food plot.
Standing corn provides exceptional fall and winter food source for whitetail deer. Plan timing so corn matures before peak rut for maximum hunting impact.
Corn timing. Live alerts.
Bield: Farm ties weather and soil-temperature stations in your county to crop planting thresholds — get notified the day soil temp clears your target window.