Blog

When to Plant Bok Choy in Kitchener-Waterloo, ON

Bok choy is a Chinese cabbage variety with crisp white stalks and dark green leaves. It is a fast-growing cool-season crop ideal for stir-fries and soups.

Kitchener-Waterloo, Ontario is in USDA Zone 7a. The average last spring frost is April 10 and the first fall frost is October 27, giving you a growing season of approximately 200 days.

At an elevation of 1,095 feet, Kitchener-Waterloo receives approximately 45.2 inches of rainfall annually with predominantly clay loam soil. Summer highs average 82°F, so choose short-season varieties of Bok Choy to ensure they mature before fall. Clay soil retains moisture well for Bok Choy, but amend with compost to improve drainage and prevent root rot.

Kitchener-Waterloo, ON (Zone 7a) Long season
200 days
Last Spring Frost April 10
200 growing days
First Fall Frost October 27

Kitchener-Waterloo Soil Profile

Soil Type

Clay Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Bok Choy Planting Risk Windows

Early Start (70% safe) ✓ Fits season (106 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: May 27 – Jul 1
Recommended (50%) ✓ Fits season (106 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: May 27 – Jul 1
Safe Start (90%) ✓ Fits season (106 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: May 27 – Jul 1

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 Bok Choy

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

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

Bok Choy Water Budget

Plant needs
0.7″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Bok Choy

Bok Choy needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Bok Choy Needs Rainfall You Supplement Action
Jan 2.2" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 3.2" 0" ❄️ Dormant
Apr 3" 5" 0" ✅ Rainfall sufficient
May 3" 4.6" 0" ✅ Rainfall sufficient
Jun 3" 5.8" 0" ✅ Rainfall sufficient
Jul 3" 4.3" 0" ✅ Rainfall sufficient
Aug 3" 4.8" 0" ✅ Rainfall sufficient
Sep 3" 3.8" 0" ✅ Rainfall sufficient
Oct 3" 3.5" 0" ✅ Rainfall sufficient
Nov 3.5" 0" ❄️ Dormant
Dec 2.8" 0" ❄️ Dormant

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

Bok Choy 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.

Bok Choy needs ~575 GDD — county provides 2,300 GDD Excellent fit

Bok Choy Planting Timeline — Kitchener-Waterloo, ON

Bok Choy Planting Calendar

Activity When Date Range
Start Indoors March 6 Mar 6 – Mar 20
Transplant Outdoors April 10 Apr 10 – Apr 24
Direct Sow March 27 Mar 27 – Apr 17
Harvest May 22 May 22 – Jun 26
Fall Sowing August 18 Aug 18 – Sep 1

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 7a

📆 Growing Season

200 days in Kitchener-Waterloo

Growing Tips for Bok Choy in Kitchener-Waterloo

Your generous 200.0-day season in Kitchener-Waterloo allows multiple plantings of Bok Choy. Sow every 20.0 days for continuous harvest.

Common pests for Bok Choy 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 for best results. Keep soil consistently moist. Harvest whole heads or cut outer leaves for a cut-and-come-again approach.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Bok Choy in Kitchener-Waterloo, ON?

Kitchener-Waterloo is in Zone 7a with an average last frost of April 10. Plan your Bok Choy planting based on this frost date — see the calendar above for exact timing.

What planting zone is Kitchener-Waterloo, ON?

Kitchener-Waterloo, Ontario is in USDA Hardiness Zone 7a. The average last spring frost is April 10 and first fall frost is October 27.

🌱

Your Kitchener-Waterloo Garden Planner — Free

A 22-page printable planner built for Kitchener-Waterloo (Zone 7a). 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 Kitchener-Waterloo, 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.