When to Plant Comfrey in Calvert County, MD
Comfrey is a vigorous perennial herb valued as a dynamic accumulator of nutrients. Its leaves make excellent mulch, compost activator, and liquid fertilizer.
Calvert County, Maryland is in USDA Zone 7a. The average last spring frost is March 30 and the first fall frost is November 10, giving you a growing season of approximately 225 days.
At an elevation of 539 feet, Calvert County receives approximately 46.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Comfrey during the growing season.
Calvert County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.9
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
Comfrey Planting Timeline — Calvert County, MD
Comfrey Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 6 | Apr 6 – Apr 20 |
| Harvest | June 8 | Jun 8 – Aug 17 |
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
6 – 7
USDA Zone
Zone 7a
Growing Season
225 days
Growing Tips for Calvert County
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
Level Up Your Garden
Comfrey in Other Locations
Frequently Asked Questions
When should I plant Comfrey in Calvert County, MD?
Calvert County is in Zone 7a with an average last frost of March 30. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.
What planting zone is Calvert County, MD?
Calvert County, Maryland is in USDA Hardiness Zone 7a. The average last spring frost is March 30 and first fall frost is November 10.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Calvert County gardeners in Zone 7a 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.