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When to plant Comfrey in Brown County County,

Brown County County's short 160-day growing season means one Comfrey planting between May 7 and May 21. No fall crop in Zone 5a.

When to Plant Comfrey in Brown County, MN

Brown County, Minnesota Zone 5a June

Brown County, Minnesota gardeners: here's your June plan

A quick June briefing for Brown County, Minnesota gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 30
Avg. first frost October 7
Soil temp (4") 65°F
Watering Low
Pest pressure High
Daylight 15.3 hrs
Coming up in July — start thinking about
  • First harvests: comfrey

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

Brown County, Minnesota is in USDA Zone 5a. The average last spring frost is April 30 and the first fall frost is October 7, giving you a growing season of approximately 160 days.

At an elevation of 1,199 feet, Brown County receives approximately 31.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Comfrey to ensure they mature before fall.

Brown County, MN (Zone 5a) Moderate season
160 days
Last Spring Frost April 30
160 growing days
First Fall Frost October 7
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Brown County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7

Drainage

Well Drained

Comfrey Planting Risk Windows

Early Start (70% safe) ✓ Fits season (18 days to spare)
Transplant: May 1 🍅 Harvest: Jul 3 – Sep 11
Recommended (50%) ✓ Fits season (20 days to spare)
Transplant: May 7 🍅 Harvest: Jul 9 – Sep 17
Safe Start (90%) ✓ Fits season (19 days to spare)
Transplant: May 22 🍅 Harvest: Jul 24 – Oct 2

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Brown County

How your county's soil matches Comfrey's growing requirements.

Soil pH

Your soil pH (6.1–7.0) is within Comfrey's preferred range (6.0–7.0).

Soil Texture

The silt loam soil in Brown County is excellent for Comfrey — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.2%) — Comfrey will thrive.

How to Plant Comfrey

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Comfrey

3
successive plantings in your 160-day season

Sow every 6.9 weeks. Last sowing by Jul 09 to harvest before frost.

Comfrey Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 282 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.2" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 3.4" 0.9" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 4" 0.3" 💧 Light watering
Jul 4.3" 3.6" 0.7" 💧 Light watering
Aug 4.3" 3.3" 1" 💧 Light watering
Sep 4.3" 2.8" 1.5" 💧 Light watering
Oct 4.3" 2" 2.3" 🚿 Regular watering
Nov 2.2" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Comfrey Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Comfrey needs ~919 GDD — county provides 1,960 GDD Excellent fit

Comfrey Planting Timeline — Brown County, MN

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors May 7 May 7 – May 21
Harvest July 9 Jul 9 – Sep 17

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
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 5a

📆 Growing Season

160 days in Brown County

Growing Tips for Comfrey in Brown County

Direct sow Comfrey outdoors after April 30 in Brown County when soil has warmed and frost danger has passed.

General growing tips

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 Brown County, MN?

Brown County is in Zone 5a with an average last frost of April 30. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.

What planting zone is Brown County, MN?

Brown County, Minnesota is in USDA Hardiness Zone 5a. The average last spring frost is April 30 and first fall frost is October 7.

When should I plant Comfrey in Brown County, ?

In Brown County, , plant Comfrey after the last frost (around April 30) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Brown County, for Comfrey?

Brown 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 Brown County's climate?

Yes — Comfrey grows well in Brown County's temperate climate. Brown County averages a 160-day frost-free season, with last frost around April 30 and first frost around October 7.

🌱

Your Brown County Garden Planner — Free

A 22-page printable planner built for Brown 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 Brown County, MN. Local conditions may vary. Last updated: June 2026.

Sources & credits

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