When to Plant Comfrey in Douglas County, MN
Comfrey is a vigorous perennial herb valued as a dynamic accumulator of nutrients. Its leaves make excellent mulch, compost activator, and liquid fertilizer.
Douglas County, Minnesota is in USDA Zone 4a. The average last spring frost is May 3 and the first fall frost is October 4, giving you a growing season of approximately 154 days.
At an elevation of 1,010 feet, Douglas County receives approximately 37.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Comfrey to ensure they mature before fall.
Douglas County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-6.9
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 — Douglas County, MN
Comfrey Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 10 | May 10 – May 24 |
| Harvest | July 12 | Jul 12 – Sep 20 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| 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 4a
Growing Season
154 days
Growing Tips for Douglas 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 Douglas County, MN?
Douglas County is in Zone 4a with an average last frost of May 3. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.
What planting zone is Douglas County, MN?
Douglas County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 3 and first fall frost is October 4.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Douglas County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.
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