When to Plant Corn in Idaho County, ID
Corn is a warm-season grass grown for its sweet ears, which are best eaten soon after harvest. It is wind-pollinated and must be planted in blocks for good kernel fill.
Idaho County, Idaho is in USDA Zone 5a. The average last spring frost is May 29 and the first fall frost is September 20, giving you a growing season of approximately 114 days.
At an elevation of 6,736 feet, Idaho County receives approximately 24.5 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Corn to ensure they mature before fall.
Idaho County Soil Profile
Soil Type
Loam
Soil pH
6.3-7.8
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Corn Planting Timeline — Idaho County, ID
Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | June 5 | Jun 5 – Jun 26 |
| Harvest | August 7 | Aug 7 – Oct 2 |
Plant 1" deep · 12" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Direct Sow |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
60–100 days
Soil pH
6 – 7
USDA Zone
Zone 5a
Growing Season
114 days
Growing Tips for Idaho County
Plant in blocks of at least 4 rows rather than single rows for proper pollination. Direct sow after soil reaches 60F. Side-dress with nitrogen when plants are knee-high.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Corn in Other Locations
Frequently Asked Questions
When should I plant Corn in Idaho County, ID?
Idaho County is in Zone 5a with an average last frost of May 29. Plan your Corn planting based on this frost date — see the calendar above for exact timing.
What planting zone is Idaho County, ID?
Idaho County, Idaho is in USDA Hardiness Zone 5a. The average last spring frost is May 29 and first fall frost is September 20.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Idaho County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.