When to Plant Sweet Corn in Larimer County, CO
Sweet corn is bred for high sugar content in its kernels, which convert to starch rapidly after harvest. Modern supersweet varieties hold their sweetness longer.
Larimer County, Colorado is in USDA Zone 5a. The average last spring frost is May 2 and the first fall frost is October 6, giving you a growing season of approximately 157 days.
At an elevation of 7,108 feet, Larimer County receives approximately 23.4 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Sweet Corn to ensure they mature before fall.
Larimer County Soil Profile
Soil Type
Loam
Soil pH
6.4-8.2
Drainage
Well Drained
Sweet Corn Planting Timeline — Larimer County, CO
Sweet Corn Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | May 9 | May 9 – May 30 |
| Harvest | July 11 | Jul 11 – Aug 22 |
Plant 1" deep · 12" apart · Rows 36" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
60–90 days
Soil pH
6 – 7
USDA Zone
Zone 5a
Growing Season
157 days
Growing Tips for Larimer County
Plant in blocks of at least 4 rows for wind pollination. Direct sow after soil is warm. Isolate supersweet varieties from other corn types to prevent cross-pollination.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Sweet Corn in Other Locations
Frequently Asked Questions
When should I plant Sweet Corn in Larimer County, CO?
Larimer County is in Zone 5a with an average last frost of May 2. Plan your Sweet Corn planting based on this frost date — see the calendar above for exact timing.
What planting zone is Larimer County, CO?
Larimer County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is May 2 and first fall frost is October 6.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Larimer County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.
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