When to Plant Comfrey in London, ON
Comfrey is a vigorous perennial herb valued as a dynamic accumulator of nutrients. Its leaves make excellent mulch, compost activator, and liquid fertilizer.
London, Ontario is in USDA Zone 7b. The average last spring frost is April 3 and the first fall frost is October 27, giving you a growing season of approximately 207 days.
At an elevation of 823 feet, London receives approximately 36.1 inches of rainfall annually with predominantly clay loam soil. Summer highs average 87°F, providing good warmth for Comfrey during the growing season. Clay soil retains moisture well for Comfrey, but amend with compost to improve drainage and prevent root rot.
London Soil Profile
Soil Type
Clay Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Comfrey Planting Timeline — London, ON
Comfrey Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 10 | Apr 10 – Apr 24 |
| Harvest | June 12 | Jun 12 – Aug 21 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 7b
📆 Growing Season
207 days in London
Growing Tips for London
Plant root cuttings 2 inches deep. Choose Bocking 14 variety to prevent self-seeding. Cut leaves 3-4 times per season for mulch or compost. Avoid planting near pathways as it spreads.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Comfrey in Other Locations
Frequently Asked Questions
When should I plant Comfrey in London, ON?
London is in Zone 7b with an average last frost of April 3. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.
What planting zone is London, ON?
London, Ontario is in USDA Hardiness Zone 7b. The average last spring frost is April 3 and first fall frost is October 27.
Your London Garden Planner — Free
A 22-page printable planner built for London (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.