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When to Plant Comfrey in Howard 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.

Howard County, Missouri is in USDA Zone 6a. The average last spring frost is April 13 and the first fall frost is October 24, giving you a growing season of approximately 194 days.

At an elevation of 945 feet, Howard County receives approximately 41.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91ยฐF, providing good warmth for Comfrey during the growing season.

Howard County, MO (Zone 6a) Moderate season
194 days
Last Spring Frost April 13
194 growing days
First Fall Frost October 24

Howard County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (53 days to spare)
Transplant: Apr 13 🍅 Harvest: Jun 15 – Aug 24
Recommended (50%) ✓ Fits season (54 days to spare)
Transplant: Apr 20 🍅 Harvest: Jun 22 – Aug 31
Safe Start (90%) ✓ Fits season (49 days to spare)
Transplant: May 6 🍅 Harvest: Jul 8 – Sep 16

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
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 219 gal / 100 sq ft
Drought risk

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

Comfrey needs ~1,369 GDD — county provides 3,540 GDD Excellent fit

Comfrey Planting Timeline โ€” Howard County, MO

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors April 20 Apr 20 โ€“ May 4
Harvest June 22 Jun 22 โ€“ Aug 31

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 6a

Growing Season

194 days

Growing Tips for Howard 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 Howard County, MO?

Howard County is in Zone 6a with an average last frost of April 13. Plan your Comfrey planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Howard County, MO?

Howard County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 13 and first fall frost is October 24.

๐ŸŒฑ

Plan Your Garden with Confidence

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