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When to Plant Borage in Dane County, WI

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.

Dane County, Wisconsin is in USDA Zone 5a. The average last spring frost is April 30 and the first fall frost is October 9, giving you a growing season of approximately 162 days.

At an elevation of 649 feet, Dane County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Borage during the growing season.

Dane County, WI (Zone 5a) Moderate season
162 days
Last Spring Frost April 30
162 growing days
First Fall Frost October 9

Dane County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (64 days to spare)
Start indoors: Mar 21 Transplant: Apr 18 🍅 Harvest: Jun 13 – Aug 1
Recommended (50%) ✓ Fits season (64 days to spare)
Start indoors: Mar 26 Transplant: Apr 23 🍅 Harvest: Jun 18 – Aug 6
Safe Start (90%) ✓ Fits season (60 days to spare)
Start indoors: Apr 16 Transplant: May 14 🍅 Harvest: Jul 9 – Aug 27

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
Borage needs ~839 GDD — county provides 2,470 GDD Excellent fit

Borage Planting Timeline โ€” Dane County, WI

Borage Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 โ€“ Apr 9
Transplant Outdoors April 23 Apr 23 โ€“ May 7
Direct Sow April 16 Apr 16 โ€“ May 7
Fall Sowing July 31 Jul 31 โ€“ Aug 14
Harvest June 18 Jun 18 โ€“ Aug 6

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 Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing Harvest
August Fall Sowing 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 5a

Growing Season

162 days

Growing Tips for Dane 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 Dane County, WI?

Dane County is in Zone 5a with an average last frost of April 30. Plan your Borage planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Dane County, WI?

Dane County, Wisconsin is in USDA Hardiness Zone 5a. The average last spring frost is April 30 and first fall frost is October 9.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Dane County gardeners in Zone 5a 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 Dane County, WI. Local conditions may vary. Last updated: April 2026.