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When to plant Soybeans in Carroll County, IL

In Carroll County, plant Soybeans in spring between April 29 and May 20, once soil temps hold above 50°F. Carroll County's last frost averages April 22, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between and — roughly 80–120 days before the first frost on October 13.

When to Plant Soybeans in Carroll 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.

Carroll County, Illinois is in USDA Zone 5a. The average last spring frost is April 22 and the first fall frost is October 13, giving you a growing season of approximately 174 days.

At an elevation of 778 feet, Carroll County receives approximately 39.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Soybeans to ensure they mature before fall.

Carroll County, IL (Zone 5a) Moderate season
174 days
Last Spring Frost April 22
174 growing days
First Fall Frost October 13

Carroll County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.8

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 1.6" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 4.2" 0.1" 💧 Light watering
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.8" 0" ✅ Rainfall sufficient
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 3.7" 0.6" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Soybeans Planting Timeline — Carroll County, IL

Soybeans Planting Calendar

Activity When Date Range
Direct Sow April 29 Apr 29 – May 20
Harvest July 22 Jul 22 – Sep 16

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

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 5a

📆 Growing Season

174 days in Carroll County

Growing Tips for Carroll 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 Carroll County, IL?

Carroll County is in Zone 5a with an average last frost of April 22. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Carroll County, IL?

Carroll County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 22 and first fall frost is October 13.

When should I plant Soybeans in Carroll County, IL?

In Carroll County, IL, plant Soybeans after the last frost (around April 22) and before the first frost (around October 13). Best results when soil holds above 50°F.

What growing zone is Carroll County, IL for Soybeans?

Carroll County sits in USDA Zone 5a. Soybeans grows reliably in zones 3a through 10b, so it's a good fit here.

Can Soybeans grow in Carroll County's climate?

Yes — Soybeans grows well in Carroll County's temperate climate. Carroll County averages a 174-day frost-free season, with last frost around April 22 and first frost around October 13.

🌱

Your Carroll County Garden Planner — Free

A 22-page printable planner built for Carroll County (Zone 5a). 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 Carroll County, IL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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