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When to plant Comfrey in Alpena County, MI

Alpena County's 137-day season only supports one Comfrey planting per year. Sow between May 26 and June 9 for the best chance at full maturity before October 3.

When to Plant Comfrey in Alpena County, MI

Comfrey is a vigorous perennial herb valued as a dynamic accumulator of nutrients. Its leaves make excellent mulch, compost activator, and liquid fertilizer.

Alpena County, Michigan is in USDA Zone 5a. The average last spring frost is May 19 and the first fall frost is October 3, giving you a growing season of approximately 137 days.

At an elevation of 984 feet, Alpena County receives approximately 31.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Comfrey during the growing season.

Alpena County, MI (Zone 5a) Short season
137 days
Last Spring Frost May 19
137 growing days
First Fall Frost October 3

Alpena County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

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 1.3" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 3.3" 0" ❄️ Dormant
May 4.3" 3.4" 0.9" 💧 Light watering
Jun 4.3" 3.5" 0.8" 💧 Light watering
Jul 4.3" 3.4" 0.9" 💧 Light watering
Aug 4.3" 2.9" 1.4" 💧 Light watering
Sep 4.3" 3" 1.3" 💧 Light watering
Oct 4.3" 2.2" 2.1" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Alpena County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Comfrey Planting Timeline — Alpena County, MI

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors May 26 May 26 – Jun 9
Harvest July 28 Jul 28 – Oct 6

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Transplant Outdoors
July Harvest
August Harvest
September Harvest
October Harvest
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

137 days in Alpena County

Growing Tips for Alpena 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 →

Frequently Asked Questions

When should I plant Comfrey in Alpena County, MI?

Alpena County is in Zone 5a with an average last frost of May 19. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.

What planting zone is Alpena County, MI?

Alpena County, Michigan is in USDA Hardiness Zone 5a. The average last spring frost is May 19 and first fall frost is October 3.

When should I plant Comfrey in Alpena County, MI?

In Alpena County, MI, plant Comfrey after the last frost (around May 19) and before the first frost (around October 3). Best results when soil holds above 50°F.

What growing zone is Alpena County, MI for Comfrey?

Alpena 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 Alpena County's climate?

Yes — Comfrey grows well in Alpena County's temperate climate. Alpena County averages a 137-day frost-free season, with last frost around May 19 and first frost around October 3.

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Your Alpena County Garden Planner — Free

A 22-page printable planner built for Alpena 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Alpena County, MI. Local conditions may vary. Last updated: July 2026.

Sources & credits

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