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When to Plant Borage in Allen County, OH

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.

Allen County, Ohio is in USDA Zone 5b. The average last spring frost is April 23 and the first fall frost is October 22, giving you a growing season of approximately 182 days.

At an elevation of 593 feet, Allen County receives approximately 40.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Borage during the growing season.

Allen County, OH (Zone 5b) Moderate season
182 days
Last Spring Frost April 23
182 growing days
First Fall Frost October 22

Allen County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (86 days to spare)
Start indoors: Mar 11 Transplant: Apr 8 🍅 Harvest: Jun 3 – Jul 22
Recommended (50%) ✓ Fits season (84 days to spare)
Start indoors: Mar 19 Transplant: Apr 16 🍅 Harvest: Jun 11 – Jul 30
Safe Start (90%) ✓ Fits season (81 days to spare)
Start indoors: Apr 1 Transplant: Apr 29 🍅 Harvest: Jun 24 – Aug 12

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
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Borage needs ~756 GDD — county provides 2,502 GDD Excellent fit

Borage Planting Timeline โ€” Allen County, OH

Borage Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 โ€“ Apr 2
Transplant Outdoors April 16 Apr 16 โ€“ Apr 30
Direct Sow April 9 Apr 9 โ€“ Apr 30
Fall Sowing August 13 Aug 13 โ€“ Aug 27
Harvest June 11 Jun 11 โ€“ Jul 30

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Start Indoors 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

182 days

Growing Tips for Allen 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 Allen County, OH?

Allen County is in Zone 5b with an average last frost of April 23. Plan your Borage planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Allen County, OH?

Allen County, Ohio is in USDA Hardiness Zone 5b. The average last spring frost is April 23 and first fall frost is October 22.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Allen 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 Allen County, OH. Local conditions may vary. Last updated: April 2026.