When to Plant Garlic in Ottawa, ON
Garlic is a pungent allium planted in fall and harvested the following summer. Hardneck varieties produce edible flower stalks (scapes) and are more cold-hardy.
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 Garlic to ensure they mature before fall. Clay soil retains moisture well for Garlic, but amend with compost to improve drainage and prevent root rot.
Ottawa Soil Profile
Soil Type
Clay Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Garlic Planting Timeline — Ottawa, ON
Garlic Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Harvest | December 5 | Dec 5 – Mar 20 |
| Fall Sowing | September 5 | Sep 5 – Sep 19 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Harvest |
| February | Harvest |
| March | Harvest |
| April | — |
| May | — |
| June | — |
| July | — |
| August | — |
| September | Fall Sowing |
| October | — |
| November | — |
| December | Harvest |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
90–240 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 6b
📆 Growing Season
187 days in Ottawa
Growing Tips for Ottawa
Plant individual cloves pointed end up in fall, 6 weeks before ground freezes. Mulch heavily with straw. Harvest when lower leaves begin to brown but 5-6 green leaves remain.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Garlic in Other Locations
Frequently Asked Questions
When should I plant Garlic in Ottawa, ON?
Ottawa is in Zone 6b with an average last frost of April 13. Plan your Garlic 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.