When to Plant Comfrey in Warren County, IA
Comfrey is a vigorous perennial herb valued as a dynamic accumulator of nutrients. Its leaves make excellent mulch, compost activator, and liquid fertilizer.
Warren County, Iowa is in USDA Zone 5a. The average last spring frost is April 26 and the first fall frost is October 9, giving you a growing season of approximately 166 days.
At an elevation of 853 feet, Warren County receives approximately 30.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Comfrey during the growing season.
Warren County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-6.7
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 — Warren County, IA
Comfrey Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 3 | May 3 – May 17 |
| Harvest | July 5 | Jul 5 – Sep 13 |
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 5a
Growing Season
166 days
Growing Tips for Warren 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 Warren County, IA?
Warren County is in Zone 5a with an average last frost of April 26. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.
What planting zone is Warren County, IA?
Warren County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 26 and first fall frost is October 9.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Warren County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.
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