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When to Plant Cabbage in Thunder Bay, ON

Cabbage

Cabbage is a versatile cool-season crop that forms dense, leafy heads in green, red, or savoy varieties. It is a staple for coleslaw, sauerkraut, and many global cuisines.

Thunder Bay, Ontario is in USDA Zone 4b. The average last spring frost is May 7 and the first fall frost is October 1, giving you a growing season of approximately 147 days.

At an elevation of 652 feet, Thunder Bay receives approximately 20.5 inches of rainfall annually with predominantly clay loam soil. Summer highs average 72°F, so choose short-season varieties of Cabbage to ensure they mature before fall. Clay soil retains moisture well for Cabbage, but amend with compost to improve drainage and prevent root rot.

Thunder Bay, ON (Zone 4b) Short season
147 days
Last Spring Frost May 7
147 growing days
First Fall Frost October 1

Thunder Bay Soil Profile

Soil Type

Clay Loam

Soil pH

6.0-7.0

Drainage

Well Drained

How Much Cabbage to Grow

2-4 lbs
Average yield per plant
3
Plants per person
6 sq ft
Space per person

For a family of 4, plant approximately 12 cabbage plants in about 24 sq ft. In Thunder Bay's 147-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Cabbage Planting Timeline — Thunder Bay, ON

Cabbage Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors May 7 May 7 – May 21
Direct Sow April 30 Apr 30 – May 21
Harvest July 9 Jul 9 – Sep 3
Fall Sowing July 9 Jul 9 – Jul 23

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 4b

📆 Growing Season

147 days in Thunder Bay

Growing Tips for Thunder Bay

Start seeds indoors 4-6 weeks before last frost. Space plants 18-24 inches apart. Keep soil evenly moist to prevent heads from splitting.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cabbage in Thunder Bay, ON?

Thunder Bay is in Zone 4b with an average last frost of May 7. Plan your Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Thunder Bay, ON?

Thunder Bay, Ontario is in USDA Hardiness Zone 4b. The average last spring frost is May 7 and first fall frost is October 1.

🌱

Your Thunder Bay Garden Planner — Free

A 22-page printable planner built for Thunder Bay (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.