Blog

When to Plant Comfrey in Scott 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.

Scott County, Minnesota is in USDA Zone 4a. 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 80ยฐF, so choose short-season varieties of Comfrey to ensure they mature before fall.

Scott County, MN (Zone 4a) 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.

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
Comfrey needs ~750 GDD — county provides 1,680 GDD Excellent fit

Comfrey Planting Timeline โ€” Scott County, MN

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors May 1 May 1 โ€“ May 15
Harvest July 3 Jul 3 โ€“ Sep 11

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Transplant Outdoors
June โ€”
July Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“90 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4a

Growing Season

168 days

Growing Tips for Scott 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Comfrey in Scott County, MN?

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

What planting zone is Scott County, MN?

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

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Scott County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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: April 2026.