When to Plant Borage in Delta County, MI
Borage is a self-seeding annual herb with star-shaped blue flowers that attract pollinators. Its leaves have a cucumber-like flavor and the flowers are edible.
Delta County, Michigan is in USDA Zone 4b. The average last spring frost is May 12 and the first fall frost is October 14, giving you a growing season of approximately 155 days.
At an elevation of 921 feet, Delta County receives approximately 41.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Borage to ensure they mature before fall.
Delta County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-6.8
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
Borage Planting Timeline — Delta County, MI
Borage Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 31 | Mar 31 – Apr 14 |
| Transplant Outdoors | May 5 | May 5 – May 19 |
| Direct Sow | May 5 | May 5 – May 26 |
| Fall Sowing | July 22 | Jul 22 – Aug 5 |
| Harvest | June 30 | Jun 30 – Aug 18 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | Fall Sowing Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Low — drought tolerant
Days to Maturity
50–60 days
Soil pH
6 – 7
USDA Zone
Zone 4b
Growing Season
155 days
Growing Tips for Delta County
Direct sow in spring as borage does not transplant well. Allow some plants to go to seed for next year. Young leaves are best; older leaves become bristly.
Companion Planting
Good Companions
Level Up Your Garden
Borage in Other Locations
Frequently Asked Questions
When should I plant Borage in Delta County, MI?
Delta County is in Zone 4b with an average last frost of May 12. Plan your Borage planting based on this frost date — see the calendar above for exact timing.
What planting zone is Delta County, MI?
Delta County, Michigan is in USDA Hardiness Zone 4b. The average last spring frost is May 12 and first fall frost is October 14.
Plan Your Garden with Confidence
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