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When to Plant Comfrey in Benton 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.

Benton County, Missouri is in USDA Zone 6a. The average last spring frost is April 9 and the first fall frost is October 25, giving you a growing season of approximately 199 days.

At an elevation of 1,323 feet, Benton County receives approximately 39.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Comfrey during the growing season.

Benton County, MO (Zone 6a) Moderate season
199 days
Last Spring Frost April 9
199 growing days
First Fall Frost October 25

Benton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.6

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 (59 days to spare)
Transplant: Apr 16 🍅 Harvest: Jun 18 – Aug 27
Safe Start (90%) ✓ Fits season (55 days to spare)
Transplant: May 5 🍅 Harvest: Jul 7 – Sep 15

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 Benton County

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

Soil pH

Your soil pH (5.3โ€“6.6) is more acidic than Comfrey prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Benton County is excellent for Comfrey โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Comfrey.

Organic Matter

Organic matter is moderate (3.2%). Annual compost additions will help Comfrey.

How to Plant Comfrey

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

Succession Planting Comfrey

3
successive plantings in your 199-day season

Sow every 6.9 weeks. Last sowing by Jul 27 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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

Comfrey needs ~1,312 GDD — county provides 3,482 GDD Excellent fit

Comfrey Planting Timeline โ€” Benton County, MO

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors April 16 Apr 16 โ€“ Apr 30
Harvest June 18 Jun 18 โ€“ Aug 27

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 โ€”
June Harvest
July Harvest
August Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

199 days in Benton County

Growing Tips for Comfrey in Benton County

Direct sow Comfrey outdoors after April 09 in Benton 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Comfrey in Benton County, MO?

Benton County is in Zone 6a with an average last frost of April 9. Plan your Comfrey planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Benton County, MO?

Benton County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 9 and first fall frost is October 25.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Benton County gardeners in Zone 6a 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 Benton County, MO. Local conditions may vary. Last updated: April 2026.