When to plant Comfrey in Humboldt County, IA
Humboldt County sits in cold Zone 5a. Plant Comfrey May 6–May 20 for the single annual harvest; the October 6 first frost closes the window.
When to Plant Comfrey in Humboldt 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.
Humboldt County, Iowa is in USDA Zone 5a. The average last spring frost is April 29 and the first fall frost is October 6, giving you a growing season of approximately 160 days.
At an elevation of 822 feet, Humboldt County receives approximately 31.6 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.
Humboldt County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Comfrey Planting Timeline — Humboldt County, IA
Comfrey Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 6 | May 6 – May 20 |
| Harvest | July 8 | Jul 8 – Sep 16 |
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
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 5a
📆 Growing Season
160 days in Humboldt County
Growing Tips for Humboldt 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
Check more plant combinations with our Companion Planting Checker →
Comfrey in Other Locations
Frequently Asked Questions
When should I plant Comfrey in Humboldt County, IA?
Humboldt County is in Zone 5a with an average last frost of April 29. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.
What planting zone is Humboldt County, IA?
Humboldt County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 29 and first fall frost is October 6.
When should I plant Comfrey in Humboldt County, IA?
In Humboldt County, IA, plant Comfrey after the last frost (around April 29) and before the first frost (around October 6). Best results when soil holds above 50°F.
What growing zone is Humboldt County, IA for Comfrey?
Humboldt County sits in USDA Zone 5a. Comfrey grows reliably in zones 3a through 9b, so it's a good fit here.
Can Comfrey grow in Humboldt County's climate?
Yes — Comfrey grows well in Humboldt County's temperate climate. Humboldt County averages a 160-day frost-free season, with last frost around April 29 and first frost around October 6.
Your Humboldt County Garden Planner — Free
A 22-page printable planner built for Humboldt County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.