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When to Plant Comfrey in Madison County, MO

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

Madison County, Missouri is in USDA Zone 6b. The average last spring frost is April 10 and the first fall frost is October 25, giving you a growing season of approximately 198 days.

At an elevation of 888 feet, Madison County receives approximately 37.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Comfrey during the growing season.

Madison County, MO (Zone 6b) Moderate season
198 days
Last Spring Frost April 10
198 growing days
First Fall Frost October 25

Madison County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (56 days to spare)
Transplant: Apr 11 🍅 Harvest: Jun 13 – Aug 22
Recommended (50%) ✓ Fits season (58 days to spare)
Transplant: Apr 17 🍅 Harvest: Jun 19 – Aug 28
Safe Start (90%) ✓ Fits season (56 days to spare)
Transplant: Apr 30 🍅 Harvest: Jul 2 – Sep 10

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
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 446 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Comfrey needs ~1,144 GDD — county provides 3,019 GDD Excellent fit

Comfrey Planting Timeline โ€” Madison County, MO

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors April 17 Apr 17 โ€“ May 1
Harvest June 19 Jun 19 โ€“ Aug 28

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Transplant Outdoors
May Transplant Outdoors
June Harvest
July Harvest
August Harvest
September โ€”
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 6b

Growing Season

198 days

Growing Tips for Madison 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 Madison County, MO?

Madison County is in Zone 6b with an average last frost of April 10. Plan your Comfrey planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Madison County, MO?

Madison County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 10 and first fall frost is October 25.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Madison County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

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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 Madison County, MO. Local conditions may vary. Last updated: April 2026.