When to Plant Collard Greens in Ontonagon County, MI
Collard greens are a heat-tolerant member of the cabbage family with large, sturdy leaves. They are a Southern staple and one of the most nutritious leafy greens.
Ontonagon County, Michigan is in USDA Zone 4a. The average last spring frost is May 22 and the first fall frost is September 28, giving you a growing season of approximately 129 days.
At an elevation of 502 feet, Ontonagon County receives approximately 42 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Collard Greens to ensure they mature before fall.
Ontonagon 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
Collard Greens Planting Timeline — Ontonagon County, MI
Collard Greens Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 10 | Apr 10 – Apr 24 |
| Transplant Outdoors | May 22 | May 22 – Jun 5 |
| Direct Sow | May 15 | May 15 – Jun 5 |
| Fall Sowing | July 6 | Jul 6 – Jul 20 |
| Harvest | July 17 | Jul 17 – Sep 18 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
55–75 days
Soil pH
6 – 7
USDA Zone
Zone 4a
Growing Season
129 days
Growing Tips for Ontonagon County
Start seeds indoors or direct sow 4-6 weeks before last frost. Harvest lower leaves first, leaving the growing tip intact. Flavor improves after exposure to frost.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Collard Greens in Other Locations
Frequently Asked Questions
When should I plant Collard Greens in Ontonagon County, MI?
Ontonagon County is in Zone 4a with an average last frost of May 22. Plan your Collard Greens planting based on this frost date — see the calendar above for exact timing.
What planting zone is Ontonagon County, MI?
Ontonagon County, Michigan is in USDA Hardiness Zone 4a. The average last spring frost is May 22 and first fall frost is September 28.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Ontonagon County gardeners in Zone 4a 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.