When to plant Borage in St. Clair County, MI
Spring Borage in St. Clair County goes in April 13–May 4, once nighttime temps stop dipping near freezing. A second sowing from August 18 to September 1 extends the harvest into fall.
When to Plant Borage in St. Clair 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.
St. Clair County, Michigan is in USDA Zone 6a. The average last spring frost is April 27 and the first fall frost is October 27, giving you a growing season of approximately 183 days.
At an elevation of 1,065 feet, St. Clair County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Borage during the growing season.
St. Clair County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-7.2
Drainage
Well Drained
Monthly Watering Guide for Borage
Borage needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Borage Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 3" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| May | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Jun | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Oct | 4.3" | 3.3" | 1" | 💧 Light watering |
| Nov | — | 2.7" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in St. Clair County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Borage Planting Timeline — St. Clair County, MI
Borage Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 23 | Mar 23 – Apr 6 |
| Transplant Outdoors | April 20 | Apr 20 – May 4 |
| Direct Sow | April 13 | Apr 13 – May 4 |
| Harvest | June 15 | Jun 15 – Aug 3 |
| Fall Sowing | August 18 | Aug 18 – Sep 1 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
50–60 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 6a
📆 Growing Season
183 days in St. Clair County
Growing Tips for St. Clair 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
Check more plant combinations with our Companion Planting Checker →
Borage in Other Locations
Frequently Asked Questions
When should I plant Borage in St. Clair County, MI?
St. Clair County is in Zone 6a with an average last frost of April 27. Plan your Borage planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Clair County, MI?
St. Clair County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is April 27 and first fall frost is October 27.
When should I plant Borage in St. Clair County, MI?
In St. Clair County, MI, plant Borage after the last frost (around April 27) and before the first frost (around October 27). Best results when soil holds above 50°F.
What growing zone is St. Clair County, MI for Borage?
St. Clair County sits in USDA Zone 6a. Borage grows reliably in zones 3a through 11b, so it's a good fit here.
Can Borage grow in St. Clair County's climate?
Yes — Borage grows well in St. Clair County's temperate climate. St. Clair County averages a 183-day frost-free season, with last frost around April 27 and first frost around October 27.
Your St. Clair County Garden Planner — Free
A 22-page printable planner built for St. Clair County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.