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When to Plant Chard in Ottawa, ON

Swiss chard is a colorful, heat-tolerant green with large crinkled leaves and vibrant stalks in red, yellow, and white. Both the leaves and stems are edible and nutritious.

Ottawa, Ontario is in USDA Zone 6b. The average last spring frost is April 13 and the first fall frost is October 17, giving you a growing season of approximately 187 days.

At an elevation of 229 feet, Ottawa receives approximately 32.8 inches of rainfall annually with predominantly clay loam soil. Summer highs average 80°F, so choose short-season varieties of Chard to ensure they mature before fall. Clay soil retains moisture well for Chard, but amend with compost to improve drainage and prevent root rot.

Ottawa, ON (Zone 6b) Moderate season
187 days
Last Spring Frost April 13
187 growing days
First Fall Frost October 17

Ottawa Soil Profile

Soil Type

Clay Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Chard Planting Risk Windows

Early Start (70% safe) ✓ Fits season (78 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jun 10 – Jul 29
Recommended (50%) ✓ Fits season (78 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jun 10 – Jul 29
Safe Start (90%) ✓ Fits season (78 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jun 10 – Jul 29

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 Chard

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

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

Chard Water Budget

Plant needs
0.8″/week
Rainfall provides
0.7″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 105 gal / 100 sq ft

Monthly Watering Guide for Chard

Chard needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Chard Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 3.5" 2.8" 0.7" 💧 Light watering
May 3.5" 3.7" 0" ✅ Rainfall sufficient
Jun 3.5" 3.9" 0" ✅ Rainfall sufficient
Jul 3.5" 3.9" 0" ✅ Rainfall sufficient
Aug 3.5" 3.7" 0" ✅ Rainfall sufficient
Sep 3.5" 3.2" 0.3" 💧 Light watering
Oct 3.5" 2.6" 0.9" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

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

Chard 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.

Chard needs ~550 GDD — county provides 1,870 GDD Excellent fit

Chard Planting Timeline — Ottawa, ON

Chard Planting Calendar

Activity When Date Range
Start Indoors March 9 Mar 9 – Mar 23
Transplant Outdoors April 13 Apr 13 – Apr 27
Direct Sow March 30 Mar 30 – Apr 20
Harvest June 8 Jun 8 – Jul 27
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 Direct Sow
April Transplant Outdoors Direct Sow
May
June Harvest
July Harvest
August Fall Sowing
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.8"/week · Only during dry spells

📅 Days to Maturity

50–60 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

187 days in Ottawa

Growing Tips for Ottawa

Direct sow or transplant after last frost. Harvest outer leaves regularly to encourage continuous production. Chard tolerates both heat and light frost.

Companion Planting

Good Companions

Avoid Planting Near

  • Corn
  • Cucumbers

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Chard in Ottawa, ON?

Ottawa is in Zone 6b with an average last frost of April 13. Plan your Chard planting based on this frost date — see the calendar above for exact timing.

What planting zone is Ottawa, ON?

Ottawa, Ontario is in USDA Hardiness Zone 6b. The average last spring frost is April 13 and first fall frost is October 17.

🌱

Your Ottawa Garden Planner — Free

A 22-page printable planner built for Ottawa (Zone 6b). 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 Ottawa, ON. Local conditions may vary. Last updated: June 2026.

Sources & credits

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