When to Plant Soybeans in Cass 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.
Cass County, Illinois is in USDA Zone 5b. The average last spring frost is April 15 and the first fall frost is October 16, giving you a growing season of approximately 184 days.
At an elevation of 703 feet, Cass County receives approximately 31.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Soybeans to ensure they mature before fall.
Cass County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7.2
Drainage
Well Drained
Plant Planting Risk Windows
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 Cass County
How your county's soil matches Soybeans's growing requirements.
Soil pH
Your soil pH (6.0–7.2) overlaps with Soybeans's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Cass County is excellent for Soybeans — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Soybeans.
Organic Matter
Organic matter is moderate (4.0%). Annual compost additions will help Soybeans.
How to Plant Soybeans
Succession Planting Soybeans
Sow every 9.1 weeks. Last sowing by Jun 18 to harvest before frost.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Soybeans Planting Timeline — Cass County, IL
Soybeans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 22 | Apr 22 – May 13 |
| Harvest | July 15 | Jul 15 – Sep 9 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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 · 1-2 times/week
📅 Days to Maturity
80–120 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 5b
📆 Growing Season
184 days in Cass County
Growing Tips for Soybeans in Cass County
Direct sow Soybeans outdoors after April 15 in Cass 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
Level Up Your Garden
Soybeans in Other Locations
Frequently Asked Questions
When should I plant Soybeans in Cass County, IL?
Cass County is in Zone 5b with an average last frost of April 15. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.
What planting zone is Cass County, IL?
Cass County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 15 and first fall frost is October 16.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Cass County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.