When to Plant Soybeans in DeKalb 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.
DeKalb County, Illinois is in USDA Zone 5a. The average last spring frost is April 22 and the first fall frost is October 16, giving you a growing season of approximately 177 days.
At an elevation of 1,332 feet, DeKalb County receives approximately 34.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Soybeans during the growing season.
DeKalb County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7.2
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.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Soybeans Planting Timeline — DeKalb 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
| 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
Moderate — regular watering
Days to Maturity
80–120 days
Soil pH
6 – 7
USDA Zone
Zone 5a
Growing Season
177 days
Growing Tips for DeKalb 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
Level Up Your Garden
Soybeans in Other Locations
Frequently Asked Questions
When should I plant Soybeans in DeKalb County, IL?
DeKalb 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 DeKalb County, IL?
DeKalb County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 22 and first fall frost is October 16.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help DeKalb County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.
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