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When to Plant Borage in Monroe 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.

Monroe County, Missouri is in USDA Zone 5b. The average last spring frost is April 14 and the first fall frost is October 21, giving you a growing season of approximately 190 days.

At an elevation of 1,128 feet, Monroe County receives approximately 35.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Borage to ensure they mature before fall.

Monroe County, MO (Zone 5b) Moderate season
190 days
Last Spring Frost April 14
190 growing days
First Fall Frost October 21

Monroe County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (91 days to spare)
Start indoors: Mar 5 Transplant: Apr 2 🍅 Harvest: May 28 – Jul 16
Recommended (50%) ✓ Fits season (92 days to spare)
Start indoors: Mar 10 Transplant: Apr 7 🍅 Harvest: Jun 2 – Jul 21
Safe Start (90%) ✓ Fits season (93 days to spare)
Start indoors: Mar 20 Transplant: Apr 17 🍅 Harvest: Jun 12 – Jul 31

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

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Borage needs ~674 GDD — county provides 2,327 GDD Excellent fit

Borage Planting Timeline โ€” Monroe County, MO

Borage Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 โ€“ Mar 24
Transplant Outdoors April 7 Apr 7 โ€“ Apr 21
Direct Sow March 31 Mar 31 โ€“ Apr 21
Fall Sowing August 12 Aug 12 โ€“ Aug 26
Harvest June 2 Jun 2 โ€“ Jul 21

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May โ€”
June Harvest
July Harvest
August Fall Sowing
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

50โ€“60 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

190 days

Growing Tips for Monroe 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

Frequently Asked Questions

When should I plant Borage in Monroe County, MO?

Monroe County is in Zone 5b with an average last frost of April 14. Plan your Borage planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Monroe County, MO?

Monroe County, Missouri is in USDA Hardiness Zone 5b. The average last spring frost is April 14 and first fall frost is October 21.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Monroe County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Monroe County, MO. Local conditions may vary. Last updated: April 2026.