When to Plant Celery in Peterborough, ON
Celery is a marshland plant that requires consistent moisture and cool temperatures to produce crisp, flavorful stalks. It is a rewarding but demanding garden crop.
Peterborough, 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 656 feet, Peterborough receives approximately 40.6 inches of rainfall annually with predominantly clay loam soil. Summer highs average 81°F, so choose short-season varieties of Celery to ensure they mature before fall. Clay soil retains moisture well for Celery, but amend with compost to improve drainage and prevent root rot.
Peterborough 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.
Plant Water Budget
Celery Planting Timeline — Peterborough, ON
Celery 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 |
| Fall Sowing | August 8 | Aug 8 – Aug 22 |
| Harvest | July 6 | Jul 6 – Aug 31 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | — |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
High — keep soil consistently moist
Days to Maturity
80–120 days
Soil pH
6 – 7
USDA Zone
Zone 6b
Growing Season
187 days
Growing Tips for Peterborough
Start seeds indoors 10-12 weeks before last frost. Keep soil consistently moist and never let it dry out. Blanch stalks by mounding soil or using collars for milder flavor.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Celery in Other Locations
Frequently Asked Questions
When should I plant Celery in Peterborough, ON?
Peterborough is in Zone 6b with an average last frost of April 13. Plan your Celery planting based on this frost date — see the calendar above for exact timing.
What planting zone is Peterborough, ON?
Peterborough, Ontario is in USDA Hardiness Zone 6b. The average last spring frost is April 13 and first fall frost is October 17.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Peterborough gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.