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When to Plant Sweet Corn in Huerfano County, CO

Huerfano County, Colorado Zone 6a May

This month in Huerfano County, Colorado

May is a pivotal month for Huerfano County, Colorado gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 12
Avg. first frost September 30
Soil temp (4") 36°F
Watering High
Pest pressure Low
Daylight 14 hrs
  1. Plant sweet corn from seed, right in the garden

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

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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.

Huerfano County, Colorado is in USDA Zone 6a. The average last spring frost is May 12 and the first fall frost is September 30, giving you a growing season of approximately 141 days.

At an elevation of 7,235 feet, Huerfano County receives approximately 15.2 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Sweet Corn to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Sweet Corn successfully. Mulch heavily to conserve soil moisture.

Huerfano County, CO (Zone 6a) Short season
141 days
Last Spring Frost May 12
141 growing days
First Fall Frost September 30

Huerfano County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (30 days to spare)
Transplant: May 8 🍅 Harvest: Jul 10 – Aug 21
Recommended (50%) ✓ Fits season (36 days to spare)
Transplant: May 12 🍅 Harvest: Jul 14 – Aug 25
Safe Start (90%) ✓ Fits season (18 days to spare)
Transplant: Jun 14 🍅 Harvest: Aug 16 – Sep 27

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 Huerfano County

How your county's soil matches Sweet Corn's growing requirements.

Soil pH

Your soil pH (6.3–7.7) overlaps with Sweet Corn's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in Huerfano County is excellent for Sweet Corn — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Sweet Corn.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Sweet Corn.

How to Plant Sweet Corn

1"
Planting Depth
12"
Between Plants
36"
Between Rows

Succession Planting Sweet Corn

2
successive plantings in your 141-day season

Sow every 6.9 weeks. Last sowing by Jul 02 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.5″/week
You supply
1.8″/week
Watering frequency 2-3 times/week
Season total 2,255 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Sweet Corn

Sweet 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 Sweet Corn Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 6.5" 1.6" 4.9" 🚿 Regular watering
Jun 6.5" 1.1" 5.4" 🚿 Regular watering
Jul 6.5" 1.2" 5.3" 🚿 Regular watering
Aug 6.5" 1.8" 4.7" 🚿 Regular watering
Sep 6.5" 1.1" 5.4" 🚿 Regular watering
Oct 1.5" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Huerfano County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Sweet 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.

Sweet Corn needs ~919 GDD — county provides 1,727 GDD Excellent fit

Sweet Corn Planting Timeline — Huerfano County, CO

Sweet Corn Planting Calendar

Activity When Date Range
Direct Sow May 19 May 19 – Jun 9
Harvest July 21 Jul 21 – Sep 1

Plant 1" deep · 12" apart · Rows 36" apart

Month-by-Month Timeline

MonthActivities
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

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

141 days in Huerfano County

Growing Tips for Sweet Corn in Huerfano County

Direct sow Sweet Corn outdoors after May 12 in Huerfano County when soil has warmed and frost danger has passed.

Common pests for Sweet Corn in this region include corn earworm and corn borers. Use row covers early in the season and inspect plants weekly.

Huerfano County receives only 15" of rain annually. Sweet 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 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

  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Corn in Huerfano County, CO?

Huerfano County is in Zone 6a with an average last frost of May 12. Plan your Sweet Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Huerfano County, CO?

Huerfano County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 12 and first fall frost is September 30.

🌱

Your Huerfano County Garden Planner — Free

A 24-page printable planner built for Huerfano 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Huerfano County, CO. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.