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When to Plant Comfrey in Northampton County, PA

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

Northampton County, Pennsylvania is in USDA Zone 6b. The average last spring frost is April 20 and the first fall frost is October 24, giving you a growing season of approximately 187 days.

At an elevation of 354 feet, Northampton County receives approximately 49.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Comfrey during the growing season.

Northampton County, PA (Zone 6b) Moderate season
187 days
Last Spring Frost April 20
187 growing days
First Fall Frost October 24

Northampton County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (47 days to spare)
Transplant: Apr 20 🍅 Harvest: Jun 22 – Aug 31
Recommended (50%) ✓ Fits season (47 days to spare)
Transplant: Apr 27 🍅 Harvest: Jun 29 – Sep 7
Safe Start (90%) ✓ Fits season (37 days to spare)
Transplant: May 17 🍅 Harvest: Jul 19 – Sep 27

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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Comfrey needs ~1,144 GDD — county provides 2,851 GDD Excellent fit

Comfrey Planting Timeline โ€” Northampton County, PA

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors April 27 Apr 27 โ€“ May 11
Harvest June 29 Jun 29 โ€“ Sep 7

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 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

187 days

Growing Tips for Northampton 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 Northampton County, PA?

Northampton County is in Zone 6b with an average last frost of April 20. Plan your Comfrey planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Northampton County, PA?

Northampton County, Pennsylvania is in USDA Hardiness Zone 6b. The average last spring frost is April 20 and first fall frost is October 24.

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Plan Your Garden with Confidence

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