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When to Plant Napa Cabbage in Portage la Prairie, MB

Napa cabbage forms tall, barrel-shaped heads with tender, crinkled leaves and a mild, slightly sweet flavor. It is the primary cabbage used for kimchi.

Portage la Prairie, Manitoba is in USDA Zone 4a. The average last spring frost is May 15 and the first fall frost is October 2, giving you a growing season of approximately 140 days.

At an elevation of 853 feet, Portage la Prairie receives approximately 14.8 inches of rainfall annually with predominantly black chernozem soil. Summer highs average 69ยฐF, so choose short-season varieties of Napa Cabbage to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Napa Cabbage successfully. Mulch heavily to conserve soil moisture.

Portage la Prairie, MB (Zone 4a) Short season
140 days
Last Spring Frost May 15
140 growing days
First Fall Frost October 2

Portage la Prairie Soil Profile

Soil Type

Black Chernozem

Soil pH

6.0-7.0

Drainage

Well Drained

Monthly Watering Guide for Napa Cabbage

Napa Cabbage needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Napa Cabbage Needs Rainfall You Supplement Action
Jan โ€” 0.6" 0" โ„๏ธ Dormant
Feb โ€” 0.7" 0" โ„๏ธ Dormant
Mar โ€” 1" 0" โ„๏ธ Dormant
Apr โ€” 1.5" 0" โ„๏ธ Dormant
May 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering
Jun 4.3" 2" 2.3" ๐Ÿšฟ Regular watering
Jul 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering
Aug 4.3" 1.3" 3" ๐Ÿšฟ Regular watering
Sep 4.3" 1.2" 3.1" ๐Ÿšฟ Regular watering
Oct 4.3" 1.2" 3.1" ๐Ÿšฟ Regular watering
Nov โ€” 1" 0" โ„๏ธ Dormant
Dec โ€” 0.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Portage la Prairie). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Napa Cabbage Planting Timeline โ€” Portage la Prairie, MB

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors April 3 Apr 3 โ€“ Apr 17
Transplant Outdoors May 15 May 15 โ€“ May 29
Direct Sow May 8 May 8 โ€“ May 29
Harvest July 10 Jul 10 โ€“ Aug 14
Fall Sowing July 10 Jul 10 โ€“ Jul 24

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

High โ€” keep soil consistently moist

๐Ÿ“… Days to Maturity

55โ€“75 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

140 days in Portage la Prairie

Growing Tips for Portage la Prairie

Best grown as a fall crop. Direct sow in late summer, 60-70 days before first frost. Keep soil evenly moist. Bolt-resistant varieties are available for spring planting.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Napa Cabbage in Portage la Prairie, MB?

Portage la Prairie is in Zone 4a with an average last frost of May 15. Plan your Napa Cabbage planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Portage la Prairie, MB?

Portage la Prairie, Manitoba is in USDA Hardiness Zone 4a. The average last spring frost is May 15 and first fall frost is October 2.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Portage la Prairie gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

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Free download. Plan your entire garden season in minutes.

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