When to Plant Kale in Greater Sudbury, ON
Kale is an exceptionally hardy, nutrient-dense green available in curly, lacinato, and Russian varieties. It tolerates heavy frost and often tastes sweeter after cold exposure.
Greater Sudbury, Ontario is in USDA Zone 5b. The average last spring frost is April 24 and the first fall frost is October 8, giving you a growing season of approximately 167 days.
At an elevation of 1,141 feet, Greater Sudbury receives approximately 29.7 inches of rainfall annually with predominantly clay loam soil. Summer highs average 77°F, so choose short-season varieties of Kale to ensure they mature before fall. Clay soil retains moisture well for Kale, but amend with compost to improve drainage and prevent root rot.
Greater Sudbury Soil Profile
Soil Type
Clay Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Plant Planting Risk Windows
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 Kale
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Plant Water Budget
Monthly Watering Guide for Kale
Kale 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 | Kale Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | 3.5" | 2.9" | 0.6" | 💧 Light watering |
| May | 3.5" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 3.5" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 3.4" | 0.1" | 💧 Light watering |
| Aug | 3.5" | 3" | 0.5" | 💧 Light watering |
| Sep | 3.5" | 2.7" | 0.8" | 💧 Light watering |
| Oct | 3.5" | 2" | 1.5" | 💧 Light watering |
| Nov | — | 1.8" | 0" | ❄️ Dormant |
| Dec | — | 1.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Greater Sudbury). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Kale 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.
Kale Planting Timeline — Greater Sudbury, ON
Kale Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 20 | Mar 20 – Apr 3 |
| Transplant Outdoors | April 24 | Apr 24 – May 8 |
| Direct Sow | April 10 | Apr 10 – May 1 |
| Harvest | June 19 | Jun 19 – Aug 14 |
| Fall Sowing | July 30 | Jul 30 – Aug 13 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | Fall Sowing Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Only during dry spells
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 5b
📆 Growing Season
167 days in Greater Sudbury
Growing Tips for Kale in Greater Sudbury
Common pests for Kale 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 or transplant in early spring or late summer. Harvest outer leaves first to keep plants productive. Kale overwinters in many climates and can provide greens all year.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 1/2 mile from other brassicas (broccoli, cabbage, etc.) — they all cross.
Kale in Other Locations
Frequently Asked Questions
When should I plant Kale in Greater Sudbury, ON?
Greater Sudbury is in Zone 5b with an average last frost of April 24. Plan your Kale planting based on this frost date — see the calendar above for exact timing.
What planting zone is Greater Sudbury, ON?
Greater Sudbury, Ontario is in USDA Hardiness Zone 5b. The average last spring frost is April 24 and first fall frost is October 8.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Greater Sudbury gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
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