When to Plant Cucumber in Thunder Bay, ON
Cucumbers are a warm-season vine crop available in slicing and pickling varieties. They are prolific producers when given warmth, moisture, and a trellis to climb.
Thunder Bay, Ontario is in USDA Zone 4b. The average last spring frost is May 7 and the first fall frost is October 1, giving you a growing season of approximately 147 days.
At an elevation of 652 feet, Thunder Bay receives approximately 20.5 inches of rainfall annually with predominantly clay loam soil. Summer highs average 72°F, so choose short-season varieties of Cucumber to ensure they mature before fall. Clay soil retains moisture well for Cucumber, but amend with compost to improve drainage and prevent root rot.
Thunder Bay Soil Profile
Soil Type
Clay Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Cucumber Planting Timeline — Thunder Bay, ON
Cucumber Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 26 | Mar 26 – Apr 9 |
| Transplant Outdoors | May 28 | May 28 – Jun 11 |
| Direct Sow | May 21 | May 21 – Jun 11 |
| Harvest | July 23 | Jul 23 – Sep 17 |
Plant 0.5" deep · 24" apart · Rows 48" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
High — keep soil consistently moist
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 4b
📆 Growing Season
147 days in Thunder Bay
Growing Tips for Thunder Bay
Direct sow after last frost or start indoors 3 weeks early. Provide a trellis for vining types to save space and improve air circulation. Harvest frequently to encourage production.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Cucumber in Other Locations
Frequently Asked Questions
When should I plant Cucumber in Thunder Bay, ON?
Thunder Bay is in Zone 4b with an average last frost of May 7. Plan your Cucumber planting based on this frost date — see the calendar above for exact timing.
What planting zone is Thunder Bay, ON?
Thunder Bay, Ontario is in USDA Hardiness Zone 4b. The average last spring frost is May 7 and first fall frost is October 1.
Your Thunder Bay Garden Planner — Free
A 22-page printable planner built for Thunder Bay (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.