When to plant Comfrey in Constantine, MI
In Constantine, Comfrey is a spring-only crop. Plant May 5–May 19 once soil hits 50°F.
When to Plant Comfrey in Constantine, MI
Comfrey is a vigorous perennial herb valued as a dynamic accumulator of nutrients. Its leaves make excellent mulch, compost activator, and liquid fertilizer.
Constantine, Michigan is in USDA Zone 6a. The average last spring frost is April 28 and the first fall frost is October 16, giving you a growing season of approximately 171 days.
At an elevation of 564 feet, St. Joseph County receives approximately 39.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Comfrey to ensure they mature before fall.
Constantine Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-6.7
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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2.9" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| May | 4.3" | 5" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Sep | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Oct | 4.3" | 3" | 1.3" | 💧 Light watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in St. Joseph County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Comfrey Planting Timeline — Constantine, MI
Comfrey Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 5 | May 5 – May 19 |
| Harvest | July 7 | Jul 7 – Sep 15 |
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 6a
📆 Growing Season
171 days in St. Joseph County
Growing Tips for Constantine
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
When should I plant Comfrey in Constantine, MI?
In Constantine, MI, plant Comfrey after the last frost (around April 28) and before the first frost (around October 16). Best results when soil holds above 50°F.
What growing zone is Constantine, MI for Comfrey?
Constantine sits in USDA Zone 6a. Comfrey grows reliably in zones 3a through 9b, so it's a good fit here.
Can Comfrey grow in Constantine's climate?
Yes — Comfrey grows well in Constantine's temperate climate. Constantine averages a 171-day frost-free season, with last frost around April 28 and first frost around October 16.
Your St. Joseph County Garden Planner — Free
A 22-page printable planner built for St. Joseph County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.