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When to plant Corn in Dahlgren, IL

Dahlgren's climate puts the Corn spring window between April 16 and May 7. time plantings around the expected last-frost window for best survival.

When to Plant Corn in Dahlgren, IL

Corn
Hamilton County, Illinois Zone 6b August

Top priorities for Hamilton County, Illinois gardeners in August

Your garden in Hamilton County, Illinois is working on a schedule, even when you're not. Here's where you should be this August.

Avg. last frost April 9
Avg. first frost October 23
Soil temp (4") 81°F
Watering Moderate
Pest pressure High
Daylight 13.5 hrs
  1. Bring in the corn

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

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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.

Dahlgren, Illinois is in USDA Zone 6b. The average last spring frost is April 9 and the first fall frost is October 23, giving you a growing season of approximately 197 days.

At an elevation of 524 feet, Hamilton County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Corn during the growing season.

Dahlgren, IL (Zone 6b) Moderate season
197 days
Last Spring Frost April 9
197 growing days
First Fall Frost October 23

Dahlgren Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.7

Drainage

Well Drained

Corn Planting Risk Windows

Early Start (70% safe) ✓ Fits season (78 days to spare)
Transplant: Apr 3 🍅 Harvest: Jun 5 – Jul 31
Recommended (50%) ✓ Fits season (78 days to spare)
Transplant: Apr 9 🍅 Harvest: Jun 11 – Aug 6
Safe Start (90%) ✓ Fits season (88 days to spare)
Transplant: Apr 20 🍅 Harvest: Jun 22 – Aug 17

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 Dahlgren

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

Soil pH

Your soil pH (5.8–6.7) overlaps with Corn's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) — Corn will thrive.

How to Plant Corn

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

Succession Planting Corn

3
successive plantings in your 197-day season

Sow every 6.9 weeks. Last sowing by Jul 15 to harvest before frost.

Corn Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,407 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 1.5" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 6.5" 3.8" 2.7" 💧 Light watering
May 6.5" 4.6" 1.9" 💧 Light watering
Jun 6.5" 5.1" 1.4" 💧 Light watering
Jul 6.5" 4.2" 2.3" 💧 Light watering
Aug 6.5" 3.7" 2.8" 💧 Light watering
Sep 6.5" 3.1" 3.4" 🚿 Regular watering
Oct 6.5" 3.2" 3.3" 🚿 Regular watering
Nov 2.7" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Hamilton 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 needs ~1,400 GDD — county provides 3,447 GDD Excellent fit

Corn Planting Timeline — Dahlgren, IL

Corn Planting Calendar

Activity When Date Range
Direct Sow April 16 Apr 16 – May 7
Harvest June 18 Jun 18 – Aug 13

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Direct Sow
May Direct Sow
June Harvest
July Harvest
August Harvest
September
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: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

197 days in Hamilton County

Growing Tips for Corn in Dahlgren

Direct sow Corn outdoors after April 09 in Hamilton 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.

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

  • Tomatoes
  • Celery

Check more plant combinations with our Companion Planting Checker →

When should I plant Corn in Dahlgren, IL?

In Dahlgren, IL, plant Corn after the last frost (around April 9) and before the first frost (around October 23). Best results when soil holds above 50°F.

What growing zone is Dahlgren, IL for Corn?

Dahlgren sits in USDA Zone 6b. Corn grows reliably in zones 3a through 11b, so it's a good fit here.

Can Corn grow in Dahlgren's climate?

Yes — Corn grows well in Dahlgren's temperate climate. Dahlgren averages a 197-day frost-free season, with last frost around April 9 and first frost around October 23.

🌱

Your Hamilton County Garden Planner — Free

A 22-page printable planner built for Hamilton County (Zone 6b). 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 Hamilton County, IL. Local conditions may vary. Last updated: August 2026.