When to plant Comfrey in Clay County, MN
Clay County's 142-day season only supports one Comfrey planting per year. Sow between May 18 and June 1 for the best chance at full maturity before September 30.
When to Plant Comfrey in Clay 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.
Clay County, Minnesota is in USDA Zone 4a. The average last spring frost is May 11 and the first fall frost is September 30, giving you a growing season of approximately 142 days.
At an elevation of 1,220 feet, Clay County receives approximately 35.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Comfrey to ensure they mature before fall.
Clay County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-6.9
Drainage
Well Drained
Monthly Watering Guide for Comfrey
Comfrey needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Comfrey Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.8" | 0" | ❄️ Dormant |
| Apr | — | 3.9" | 0" | ❄️ Dormant |
| May | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Jun | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Jul | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Sep | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Oct | — | 2.6" | 0" | ❄️ Dormant |
| Nov | — | 2.2" | 0" | ❄️ Dormant |
| Dec | — | 2.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Clay County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Comfrey Planting Timeline — Clay County, MN
Comfrey Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 18 | May 18 – Jun 1 |
| Harvest | July 20 | Jul 20 – Sep 28 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | Transplant Outdoors |
| 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 4a
📆 Growing Season
142 days in Clay County
Growing Tips for Clay 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 Clay County, MN?
Clay County is in Zone 4a with an average last frost of May 11. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.
What planting zone is Clay County, MN?
Clay County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 11 and first fall frost is September 30.
When should I plant Comfrey in Clay County, MN?
In Clay County, MN, plant Comfrey after the last frost (around May 11) and before the first frost (around September 30). Best results when soil holds above 50°F.
What growing zone is Clay County, MN for Comfrey?
Clay County sits in USDA Zone 4a. Comfrey grows reliably in zones 3a through 9b, so it's a good fit here.
Can Comfrey grow in Clay County's climate?
Yes — Comfrey grows well in Clay County's temperate climate. Clay County averages a 142-day frost-free season, with last frost around May 11 and first frost around September 30.
Your Clay County Garden Planner — Free
A 22-page printable planner built for Clay County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.