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When to Plant Comfrey in Bristol County, MA

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

Bristol County, Massachusetts is in USDA Zone 6b. The average last spring frost is April 26 and the first fall frost is October 17, giving you a growing season of approximately 174 days.

At an elevation of 833 feet, Bristol County receives approximately 47.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Comfrey during the growing season.

Bristol County, MA (Zone 6b) Moderate season
174 days
Last Spring Frost April 26
174 growing days
First Fall Frost October 17

Bristol County Soil Profile

Soil Type

Silt Loam

Soil pH

5.1-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (35 days to spare)
Transplant: Apr 26 🍅 Harvest: Jun 28 – Sep 6
Recommended (50%) ✓ Fits season (34 days to spare)
Transplant: May 3 🍅 Harvest: Jul 5 – Sep 13
Safe Start (90%) ✓ Fits season (31 days to spare)
Transplant: May 21 🍅 Harvest: Jul 23 – Oct 1

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
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Comfrey needs ~1,256 GDD — county provides 2,914 GDD Excellent fit

Comfrey Planting Timeline โ€” Bristol County, MA

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors May 3 May 3 โ€“ May 17
Harvest July 5 Jul 5 โ€“ Sep 13

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 6b

Growing Season

174 days

Growing Tips for Bristol 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 Bristol County, MA?

Bristol County is in Zone 6b with an average last frost of April 26. Plan your Comfrey planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Bristol County, MA?

Bristol County, Massachusetts is in USDA Hardiness Zone 6b. The average last spring frost is April 26 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Bristol 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 Bristol County, MA. Local conditions may vary. Last updated: April 2026.