When to Plant Basil in Greater Sudbury, ON
Basil is a fragrant warm-season herb essential to Italian and Thai cuisines. It comes in many varieties including sweet, Thai, purple, and lemon types.
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 Basil to ensure they mature before fall. Clay soil retains moisture well for Basil, 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 Basil
Plant Water Budget
Monthly Watering Guide for Basil
Basil needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.
| Month | Basil Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | 2.6" | 2.9" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 3.5" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 3.4" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 3" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 2.7" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 2" | 0.6" | 💧 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.
Basil 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.
Basil Planting Timeline — Greater Sudbury, ON
Basil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 6 | Mar 6 – Mar 20 |
| Transplant Outdoors | May 8 | May 8 – May 22 |
| Direct Sow | May 1 | May 1 – May 22 |
| Harvest | July 3 | Jul 3 – Sep 4 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.6"/week · Natural rainfall sufficient
📅 Days to Maturity
50–75 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 5b
📆 Growing Season
167 days in Greater Sudbury
Growing Tips for Greater Sudbury
Start seeds indoors or direct sow after last frost. Pinch flower buds to extend leaf production. Harvest leaves from the top down, cutting just above a leaf pair.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 150 ft between varieties. Different basil species can cross.
Basil in Other Locations
Frequently Asked Questions
When should I plant Basil in Greater Sudbury, ON?
Greater Sudbury is in Zone 5b with an average last frost of April 24. Plan your Basil 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
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