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When to Plant Borage in Aitkin County, MN

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.

Aitkin County, Minnesota is in USDA Zone 3b. The average last spring frost is May 9 and the first fall frost is October 3, giving you a growing season of approximately 147 days.

At an elevation of 1,188 feet, Aitkin County receives approximately 35 inches of rainfall annually with predominantly silt loam soil. Summer highs average 78ยฐF, so choose short-season varieties of Borage to ensure they mature before fall.

Aitkin County, MN (Zone 3b) Short season
147 days
Last Spring Frost May 9
147 growing days
First Fall Frost October 3

Aitkin County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (55 days to spare)
Start indoors: Mar 20 Transplant: Apr 24 🍅 Harvest: Jun 19 – Aug 7
Recommended (50%) ✓ Fits season (49 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Jun 27 – Aug 15
Safe Start (90%) ✓ Fits season (45 days to spare)
Start indoors: Apr 14 Transplant: May 19 🍅 Harvest: Jul 14 – Sep 1

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
1.0″/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 ~468 GDD — county provides 1,249 GDD Excellent fit

Borage Planting Timeline โ€” Aitkin County, MN

Borage Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 โ€“ Apr 11
Transplant Outdoors May 2 May 2 โ€“ May 16
Direct Sow May 2 May 2 โ€“ May 23
Fall Sowing July 11 Jul 11 โ€“ Jul 25
Harvest June 27 Jun 27 โ€“ Aug 15

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
May Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing Harvest
August Harvest
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 3b

Growing Season

147 days

Growing Tips for Aitkin 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 Aitkin County, MN?

Aitkin County is in Zone 3b with an average last frost of May 9. Plan your Borage planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Aitkin County, MN?

Aitkin County, Minnesota is in USDA Hardiness Zone 3b. The average last spring frost is May 9 and first fall frost is October 3.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Aitkin County gardeners in Zone 3b 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 Aitkin County, MN. Local conditions may vary. Last updated: April 2026.