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When to plant Soybeans in Henderson County, IL

Spring Soybeans in Henderson County goes in April 24–May 15, once nighttime temps stop dipping near freezing.

When to Plant Soybeans in Henderson County, IL

Henderson County, Illinois Zone 6a August

August in the garden — Henderson County, Illinois

A quick August briefing for Henderson County, Illinois gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 17
Avg. first frost October 17
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
  1. It's harvest week for soybeans

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

September will be here before you know it — start on
  • First harvests: soybeans

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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.

Henderson County, Illinois is in USDA Zone 6a. The average last spring frost is April 17 and the first fall frost is October 17, giving you a growing season of approximately 183 days.

At an elevation of 1,278 feet, Henderson County receives approximately 41.6 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.

Henderson County, IL (Zone 6a) Moderate season
183 days
Last Spring Frost April 17
183 growing days
First Fall Frost October 17

Henderson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.3

Drainage

Well Drained

Soybeans Planting Risk Windows

Early Start (70% safe) ✓ Fits season (43 days to spare)
Transplant: Apr 11 🍅 Harvest: Jul 4 – Aug 29
Recommended (50%) ✓ Fits season (43 days to spare)
Transplant: Apr 17 🍅 Harvest: Jul 10 – Sep 4
Safe Start (90%) ✓ Fits season (44 days to spare)
Transplant: Apr 30 🍅 Harvest: Jul 23 – Sep 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 Henderson County

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

Soil pH

Your soil pH (5.7–7.3) overlaps with Soybeans's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.6%) — Soybeans will thrive.

How to Plant Soybeans

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Soybeans

2
successive plantings in your 183-day season

Sow every 9.1 weeks. Last sowing by Jun 19 to harvest before frost.

Soybeans Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 74 gal / 100 sq ft

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 1.9" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 4.3" 3.9" 0.4" 💧 Light watering
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 5.4" 0" ✅ Rainfall sufficient
Jul 4.3" 4.6" 0" ✅ Rainfall sufficient
Aug 4.3" 4.9" 0" ✅ Rainfall sufficient
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3.5" 0.8" 💧 Light watering
Nov 3.2" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

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

Soybeans 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.

Soybeans needs ~1,300 GDD — county provides 2,379 GDD Excellent fit

Soybeans Planting Timeline — Henderson County, IL

Soybeans Planting Calendar

Activity When Date Range
Direct Sow April 24 Apr 24 – May 15
Harvest July 17 Jul 17 – Sep 11

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

1"/week · Only during dry spells

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

183 days in Henderson County

Growing Tips for Soybeans in Henderson County

Direct sow Soybeans outdoors after April 17 in Henderson County when soil has warmed and frost danger has passed.

Common pests for Soybeans in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

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 Henderson County, IL?

Henderson County is in Zone 6a with an average last frost of April 17. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Henderson County, IL?

Henderson County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 17 and first fall frost is October 17.

When should I plant Soybeans in Henderson County, IL?

In Henderson County, IL, plant Soybeans after the last frost (around April 17) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Henderson County, IL for Soybeans?

Henderson County sits in USDA Zone 6a. Soybeans grows reliably in zones 3a through 10b, so it's a good fit here.

Can Soybeans grow in Henderson County's climate?

Yes — Soybeans grows well in Henderson County's temperate climate. Henderson County averages a 183-day frost-free season, with last frost around April 17 and first frost around October 17.

🌱

Your Henderson County Garden Planner — Free

A 22-page printable planner built for Henderson 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 Henderson County, IL. Local conditions may vary. Last updated: August 2026.

Sources & credits

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