When to Plant Black Beans in Cass County, MN
Black beans are a warm-season legume producing small, dark, protein-rich beans that are a staple in Latin American and Caribbean cuisines.
Cass County, Minnesota is in USDA Zone 3b. The average last spring frost is May 12 and the first fall frost is September 28, giving you a growing season of approximately 139 days.
At an elevation of 938 feet, Cass County receives approximately 32.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Black Beans to ensure they mature before fall.
Cass County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-6.9
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
Black Beans Planting Timeline — Cass County, MN
Black Beans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | May 26 | May 26 – Jun 16 |
| Harvest | August 25 | Aug 25 – Sep 29 |
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
90–120 days
Soil pH
6 – 7.5
USDA Zone
Zone 3b
Growing Season
139 days
Growing Tips for Cass County
Direct sow after last frost. Provide support for climbing varieties. Allow pods to dry fully on the vine before harvesting. Thresh dried pods by hand or in a pillowcase.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Black Beans in Other Locations
Frequently Asked Questions
When should I plant Black Beans in Cass County, MN?
Cass County is in Zone 3b with an average last frost of May 12. Plan your Black Beans planting based on this frost date — see the calendar above for exact timing.
What planting zone is Cass County, MN?
Cass County, Minnesota is in USDA Hardiness Zone 3b. The average last spring frost is May 12 and first fall frost is September 28.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Cass County gardeners in Zone 3b organize planting dates, track what's growing, and never miss a planting window.
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