When to Plant Mint in St. Joseph County, MI
Mint is a vigorous perennial herb with refreshing, aromatic leaves used in teas, cocktails, and cooking. It spreads aggressively by underground runners.
St. Joseph County, Michigan is in USDA Zone 5b. The average last spring frost is April 28 and the first fall frost is October 16, giving you a growing season of approximately 171 days.
At an elevation of 564 feet, St. Joseph County receives approximately 39.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Mint to ensure they mature before fall.
St. Joseph County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-6.7
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
Mint Planting Timeline — St. Joseph County, MI
Mint Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 5 | May 5 – May 19 |
| Harvest | July 7 | Jul 7 – Sep 15 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Partial Shade (3-6 hours)
Water
High — keep soil consistently moist
Days to Maturity
60–90 days
Soil pH
6 – 7
USDA Zone
Zone 5b
Growing Season
171 days
Growing Tips for St. Joseph County
Always grow mint in containers or with underground barriers to control spreading. Harvest regularly to keep plants compact. Cut plants back in late summer for a fresh fall flush.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Mint in Other Locations
Frequently Asked Questions
When should I plant Mint in St. Joseph County, MI?
St. Joseph County is in Zone 5b with an average last frost of April 28. Plan your Mint planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Joseph County, MI?
St. Joseph County, Michigan is in USDA Hardiness Zone 5b. The average last spring frost is April 28 and first fall frost is October 16.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help St. Joseph County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
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