When to Plant Corn in Adams County, CO
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.
Adams County, Colorado is in USDA Zone 5b. The average last spring frost is May 4 and the first fall frost is October 5, giving you a growing season of approximately 154 days.
At an elevation of 5,827 feet, Adams County receives approximately 23.9 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Corn during the growing season.
Adams County Soil Profile
Soil Type
Loam
Soil pH
6.6-7.7
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 8/10 — consider drought-tolerant varieties and mulching
Corn Planting Timeline — Adams County, CO
Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | May 11 | May 11 – Jun 1 |
| Harvest | July 13 | Jul 13 – Sep 7 |
Plant 1" deep · 12" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Direct Sow |
| June | Direct Sow |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| 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 5b
Growing Season
154 days
Growing Tips for Adams 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 Adams County, CO?
Adams County is in Zone 5b with an average last frost of May 4. Plan your Corn planting based on this frost date — see the calendar above for exact timing.
What planting zone is Adams County, CO?
Adams County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 4 and first fall frost is October 5.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Adams County gardeners in Zone 5b 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.