When to Plant Soybeans in Marshall County, MN
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.
Marshall County, Minnesota is in USDA Zone 3a. The average last spring frost is May 11 and the first fall frost is October 2, giving you a growing season of approximately 144 days.
At an elevation of 1,303 feet, Marshall County receives approximately 33.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Soybeans to ensure they mature before fall.
Marshall County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-7.3
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 — Marshall County, MN
Soybeans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | May 25 | May 25 – Jun 15 |
| Harvest | August 17 | Aug 17 – Sep 28 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Direct Sow |
| June | Direct Sow |
| July | — |
| 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 3a
Growing Season
144 days
Growing Tips for Marshall 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 Marshall County, MN?
Marshall County is in Zone 3a with an average last frost of May 11. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.
What planting zone is Marshall County, MN?
Marshall County, Minnesota is in USDA Hardiness Zone 3a. The average last spring frost is May 11 and first fall frost is October 2.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Marshall County gardeners in Zone 3a organize planting dates, track what's growing, and never miss a planting window.
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