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When to Plant Borage in Sarnia-Lambton, ON

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.

Sarnia-Lambton, Ontario is in USDA Zone 7b. The average last spring frost is April 3 and the first fall frost is October 27, giving you a growing season of approximately 207 days.

At an elevation of 590 feet, Sarnia-Lambton receives approximately 39.1 inches of rainfall annually with predominantly clay loam soil. Summer highs average 84°F, so choose short-season varieties of Borage to ensure they mature before fall. Clay soil retains moisture well for Borage, but amend with compost to improve drainage and prevent root rot.

Sarnia-Lambton, ON (Zone 7b) Long season
207 days
Last Spring Frost April 3
207 growing days
First Fall Frost October 27

Sarnia-Lambton Soil Profile

Soil Type

Clay Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Borage Planting Timeline — Sarnia-Lambton, ON

Borage Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors March 27 Mar 27 – Apr 10
Direct Sow March 20 Mar 20 – Apr 10
Harvest May 22 May 22 – Jul 10
Fall Sowing August 18 Aug 18 – Sep 1

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

50–60 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 7b

📆 Growing Season

207 days in Sarnia-Lambton

Growing Tips for Sarnia-Lambton

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Borage in Sarnia-Lambton, ON?

Sarnia-Lambton is in Zone 7b with an average last frost of April 3. Plan your Borage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sarnia-Lambton, ON?

Sarnia-Lambton, Ontario is in USDA Hardiness Zone 7b. The average last spring frost is April 3 and first fall frost is October 27.

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A 22-page printable planner built for Sarnia-Lambton (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Sarnia-Lambton, ON. Local conditions may vary. Last updated: June 2026.

Sources & credits

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