When to Plant Corn in Adams County, CO
This month in Adams County, Colorado
Each item below is timed to Adams County, Colorado's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Seed corn outdoors
Mark the row. Birds and stray feet both have opinions about unmarked beds.
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 6a. 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.
Soil Compatibility in Adams County
How your county's soil matches Corn's growing requirements.
Soil pH
Your soil pH (6.6–7.7) is more alkaline than Corn prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Adams County is excellent for Corn — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.7%). Annual compost additions will help Corn.
How to Plant Corn
Succession Planting Corn
Sow every 6.9 weeks. Last sowing by Jun 27 to harvest before frost.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Corn
Corn needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.
| Month | Corn Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | — | 2.4" | 0" | ❄️ Dormant |
| May | 6.5" | 2.5" | 4" | 🚿 Regular watering |
| Jun | 6.5" | 1.6" | 4.9" | 🚿 Regular watering |
| Jul | 6.5" | 2.1" | 4.4" | 🚿 Regular watering |
| Aug | 6.5" | 2.8" | 3.7" | 🚿 Regular watering |
| Sep | 6.5" | 1.8" | 4.7" | 🚿 Regular watering |
| Oct | 6.5" | 2.3" | 4.2" | 🚿 Regular watering |
| Nov | — | 1.5" | 0" | ❄️ Dormant |
| Dec | — | 1.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Adams County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Corn Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
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
1.5"/week · 2-3 times/week
📅 Days to Maturity
60–100 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 6a
📆 Growing Season
154 days in Adams County
Growing Tips for Corn in Adams County
Direct sow Corn outdoors after May 04 in Adams County when soil has warmed and frost danger has passed.
Common pests for Corn in this region include corn earworm and corn borers. Use row covers early in the season and inspect plants weekly.
Adams County receives only 24" of rain annually. Corn needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
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
Check more plant combinations with our Companion Planting Checker →
Corn in Other Locations
Frequently Asked Questions
When should I plant Corn in Adams County, CO?
Adams County is in Zone 6a 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 6a. The average last spring frost is May 4 and first fall frost is October 5.
Your Adams County Garden Planner — Free
A 24-page printable planner built for Adams County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.