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When to plant Soybeans in Madison County County,

Plant Soybeans in Madison County County from April 18 to May 9 in spring. Madison County County sits in USDA Zone 7a, with last frost around April 11 and first frost on October 22.

When to Plant Soybeans in Madison County, IL

Soybeans (edamame) are a high-protein legume that fixes nitrogen in the soil. Fresh green soybeans harvested at the edamame stage are a nutritious snack.

Madison County, Illinois is in USDA Zone 7a. The average last spring frost is April 11 and the first fall frost is October 22, giving you a growing season of approximately 194 days.

At an elevation of 963 feet, Madison County receives approximately 36.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Soybeans during the growing season.

Madison County, IL (Zone 7a) Moderate season
194 days
Last Spring Frost April 11
194 growing days
First Fall Frost October 22
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Madison County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.9

Drainage

Well Drained

Monthly Watering Guide for Soybeans

Soybeans needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Soybeans Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 4" 0.3" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 3.4" 0.9" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 2.8" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

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

Soybeans Planting Timeline — Madison County, IL

Soybeans Planting Calendar

Activity When Date Range
Direct Sow April 18 Apr 18 – May 9
Harvest July 11 Jul 11 – Sep 5

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Direct Sow
May Direct Sow
June
July Harvest
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 7a

📆 Growing Season

194 days in Madison County

Growing Tips for Madison County

Direct sow after soil warms to 60F. Plant in blocks rather than rows for better pollination. Harvest for edamame when pods are plump and bright green.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Soybeans in Madison County, IL?

Madison County is in Zone 7a with an average last frost of April 11. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Madison County, IL?

Madison County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 11 and first fall frost is October 22.

When should I plant Soybeans in Madison County County, ?

In Madison County County, , plant Soybeans after the last frost (around April 11) and before the first frost (around October 22). Best results when soil holds above 50°F.

What growing zone is Madison County County, for Soybeans?

Madison County County sits in USDA Zone 7a. Soybeans grows reliably in zones 3a through 10b, so it's a good fit here.

Can Soybeans grow in Madison County County's climate?

Yes — Soybeans grows well in Madison County County's temperate climate. Madison County County averages a 194-day frost-free season, with last frost around April 11 and first frost around October 22.

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Your Madison County Garden Planner — Free

A 22-page printable planner built for Madison County (Zone 7a). 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 Madison County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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