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When to Plant Pac Choi in Stormont-Dundas, ON

Pac choi (baby bok choy) is a compact variety of Chinese cabbage with tender leaves and crisp stems. It grows quickly and is ideal for containers and small spaces.

Stormont-Dundas, Ontario is in USDA Zone 6a. The average last spring frost is April 20 and the first fall frost is October 17, giving you a growing season of approximately 180 days.

At an elevation of 196 feet, Stormont-Dundas receives approximately 35.5 inches of rainfall annually with predominantly clay loam soil. Summer highs average 79°F, so choose short-season varieties of Pac Choi to ensure they mature before fall. Clay soil retains moisture well for Pac Choi, but amend with compost to improve drainage and prevent root rot.

Stormont-Dundas, ON (Zone 6a) Moderate season
180 days
Last Spring Frost April 20
180 growing days
First Fall Frost October 17

Stormont-Dundas Soil Profile

Soil Type

Clay Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Pac Choi Planting Risk Windows

Early Start (70% safe) ✓ Fits season (113 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: May 27 – Jun 24
Recommended (50%) ✓ Fits season (113 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: May 27 – Jun 24
Safe Start (90%) ✓ Fits season (113 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: May 27 – Jun 24

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.

How to Plant Pac Choi

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Pac Choi Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,076 gal / 100 sq ft

Monthly Watering Guide for Pac Choi

Pac Choi needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Pac Choi Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 6.5" 3.4" 3.1" 💧 Light watering
May 6.5" 3.7" 2.8" 💧 Light watering
Jun 6.5" 3.9" 2.6" 💧 Light watering
Jul 6.5" 4.5" 2" 💧 Light watering
Aug 6.5" 4.1" 2.4" 💧 Light watering
Sep 6.5" 2.9" 3.6" 🚿 Regular watering
Oct 6.5" 2.8" 3.7" 🚿 Regular watering
Nov 2.7" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Stormont-Dundas). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Pac Choi Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Pac Choi needs ~439 GDD — county provides 1,665 GDD Excellent fit

Pac Choi Planting Timeline — Stormont-Dundas, ON

Pac Choi Planting Calendar

Activity When Date Range
Start Indoors March 16 Mar 16 – Mar 30
Transplant Outdoors April 20 Apr 20 – May 4
Direct Sow April 6 Apr 6 – Apr 27
Harvest June 1 Jun 1 – Jun 29
Fall Sowing August 8 Aug 8 – Aug 22

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 1-2 times/week

📅 Days to Maturity

40–55 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

180 days in Stormont-Dundas

Growing Tips for Pac Choi in Stormont-Dundas

Your generous 180.0-day season in Stormont-Dundas allows multiple plantings of Pac Choi. Sow every 20.0 days for continuous harvest.

Common pests for Pac Choi in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in spring or fall. Grows best in cool weather. Space 6 inches apart for baby pac choi. Harvest whole plants or cut outer leaves as needed.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Pac Choi in Stormont-Dundas, ON?

Stormont-Dundas is in Zone 6a with an average last frost of April 20. Plan your Pac Choi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Stormont-Dundas, ON?

Stormont-Dundas, Ontario is in USDA Hardiness Zone 6a. The average last spring frost is April 20 and first fall frost is October 17.

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A 22-page printable planner built for Stormont-Dundas (Zone 6a). 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 Stormont-Dundas, 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.