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When to Plant Comfrey in Scott County, MN

Scott County, Minnesota Zone 4b May

Your May game plan for Scott County, Minnesota

We've pulled the most time-sensitive tasks for Scott County, Minnesota this May and put them front and centre. Tackle them in order.

Avg. last frost April 24
Avg. first frost October 9
Soil temp (4") 54°F
Watering Low
Pest pressure Low
Daylight 14.6 hrs
  1. Set out comfrey seedlings

    Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.

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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.

Scott County, Minnesota is in USDA Zone 4b. The average last spring frost is April 24 and the first fall frost is October 9, giving you a growing season of approximately 168 days.

At an elevation of 1,105 feet, Scott County receives approximately 39.8 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.

Scott County, MN (Zone 4b) Moderate season
168 days
Last Spring Frost April 24
168 growing days
First Fall Frost October 9

Scott County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (29 days to spare)
Transplant: Apr 24 🍅 Harvest: Jun 26 – Sep 4
Recommended (50%) ✓ Fits season (28 days to spare)
Transplant: May 1 🍅 Harvest: Jul 3 – Sep 11
Safe Start (90%) ✓ Fits season (25 days to spare)
Transplant: May 20 🍅 Harvest: Jul 22 – Sep 30

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 Scott County

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

Soil pH

Your soil pH (5.9–7.0) overlaps with Comfrey's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.5%) — 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 168-day season

Sow every 6.9 weeks. Last sowing by Jul 11 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 7 gal / 100 sq ft

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 1.6" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 4.5" 0" ✅ Rainfall sufficient
May 4.3" 4.7" 0" ✅ Rainfall sufficient
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 5" 0" ✅ Rainfall sufficient
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 3.7" 0.6" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 2.5" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Scott 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 ~750 GDD — county provides 1,680 GDD Excellent fit

Comfrey Planting Timeline — Scott County, MN

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors May 1 May 1 – May 15
Harvest July 3 Jul 3 – Sep 11

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

1"/week · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

168 days in Scott County

Growing Tips for Comfrey in Scott County

Direct sow Comfrey outdoors after April 24 in Scott 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 Scott County, MN?

Scott County is in Zone 4b with an average last frost of April 24. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.

What planting zone is Scott County, MN?

Scott County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is April 24 and first fall frost is October 9.

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Your Scott County Garden Planner — Free

A 24-page printable planner built for Scott 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 Scott County, MN. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.