When to Plant Borage in St. Clair County, MO
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, Missouri is in USDA Zone 6a. The average last spring frost is April 8 and the first fall frost is October 26, giving you a growing season of approximately 201 days.
At an elevation of 699 feet, St. Clair County receives approximately 41.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Borage during the growing season.
St. Clair County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.7
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
Borage Planting Timeline — St. Clair County, MO
Borage Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 4 | Mar 4 – Mar 18 |
| Transplant Outdoors | April 1 | Apr 1 – Apr 15 |
| Direct Sow | March 25 | Mar 25 – Apr 15 |
| Fall Sowing | August 17 | Aug 17 – Aug 31 |
| Harvest | May 27 | May 27 – Jul 15 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| 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 6a
Growing Season
201 days
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
Level Up Your Garden
Borage in Other Locations
Frequently Asked Questions
When should I plant Borage in St. Clair County, MO?
St. Clair County is in Zone 6a with an average last frost of April 8. Plan your Borage planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Clair County, MO?
St. Clair County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 8 and first fall frost is October 26.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help St. Clair County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.
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