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When to plant Comfrey in Chisago County, MN

Plant Comfrey in Chisago County during the brief May 10–May 24 window. With 151 frost-free days, fall plantings can't mature before October 1.

When to Plant Comfrey in Chisago 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.

Chisago County, Minnesota is in USDA Zone 4b. The average last spring frost is May 3 and the first fall frost is October 1, giving you a growing season of approximately 151 days.

At an elevation of 1,324 feet, Chisago County receives approximately 36.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82°F, so choose short-season varieties of Comfrey to ensure they mature before fall.

Chisago County, MN (Zone 4b) Moderate season
151 days
Last Spring Frost May 3
151 growing days
First Fall Frost October 1

Chisago County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

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 1.6" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 3.6" 0" ❄️ Dormant
May 4.3" 4.6" 0" ✅ Rainfall sufficient
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 3.7" 0.6" 💧 Light watering
Aug 4.3" 4.4" 0" ✅ Rainfall sufficient
Sep 4.3" 2.9" 1.4" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

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

Comfrey Planting Timeline — Chisago County, MN

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors May 10 May 10 – May 24
Harvest July 12 Jul 12 – Sep 20

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

Month-by-Month Timeline

MonthActivities
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 4b

📆 Growing Season

151 days in Chisago County

Growing Tips for Chisago 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 Chisago County, MN?

Chisago County is in Zone 4b with an average last frost of May 3. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.

What planting zone is Chisago County, MN?

Chisago County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is May 3 and first fall frost is October 1.

When should I plant Comfrey in Chisago County, MN?

In Chisago County, MN, plant Comfrey after the last frost (around May 3) and before the first frost (around October 1). Best results when soil holds above 50°F.

What growing zone is Chisago County, MN for Comfrey?

Chisago County sits in USDA Zone 4b. Comfrey grows reliably in zones 3a through 9b, so it's a good fit here.

Can Comfrey grow in Chisago County's climate?

Yes — Comfrey grows well in Chisago County's temperate climate. Chisago County averages a 151-day frost-free season, with last frost around May 3 and first frost around October 1.

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Your Chisago County Garden Planner — Free

A 22-page printable planner built for Chisago County (Zone 4b). 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 Chisago County, MN. Local conditions may vary. Last updated: July 2026.

Sources & credits

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