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When to Plant Comfrey in Morris County, NJ

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

Morris County, New Jersey is in USDA Zone 6b. The average last spring frost is March 29 and the first fall frost is November 12, giving you a growing season of approximately 228 days.

At an elevation of 227 feet, Morris County receives approximately 40.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91ยฐF, providing good warmth for Comfrey during the growing season.

Morris County, NJ (Zone 6b) Long season
228 days
Last Spring Frost March 29
228 growing days
First Fall Frost November 12

Morris County Soil Profile

Soil Type

Silt Loam

Soil pH

5.1-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (88 days to spare)
Transplant: Apr 1 🍅 Harvest: Jun 3 – Aug 12
Recommended (50%) ✓ Fits season (88 days to spare)
Transplant: Apr 5 🍅 Harvest: Jun 7 – Aug 16
Safe Start (90%) ✓ Fits season (97 days to spare)
Transplant: Apr 16 🍅 Harvest: Jun 18 – Aug 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.

Soil Compatibility in Morris County

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

Soil pH

Your soil pH (5.1โ€“6.5) is more acidic than Comfrey prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Comfrey.

How to Plant Comfrey

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

Succession Planting Comfrey

4
successive plantings in your 228-day season

Sow every 6.9 weeks. Last sowing by Aug 14 to harvest before frost.

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 504 gal / 100 sq ft

Monthly Watering Guide for Comfrey

Comfrey needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Comfrey Needs Rainfall You Supplement Action
Jan โ€” 3.1" 0" โ„๏ธ Dormant
Feb โ€” 2.6" 0" โ„๏ธ Dormant
Mar 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Apr 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
May 4.3" 3.2" 1.1" ๐Ÿ’ง Light watering
Jun 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Jul 4.3" 4.7" 0" โœ… Rainfall sufficient
Aug 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Sep 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Oct 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Nov 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Dec โ€” 2.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Morris County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Comfrey Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Comfrey needs ~1,369 GDD — county provides 4,161 GDD Excellent fit

Comfrey Planting Timeline โ€” Morris County, NJ

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors April 5 Apr 5 โ€“ Apr 19
Harvest June 7 Jun 7 โ€“ Aug 16

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 Only during dry spells

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

228 days in Morris County

Growing Tips for Comfrey in Morris County

Direct sow Comfrey outdoors after March 29 in Morris 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Comfrey in Morris County, NJ?

Morris County is in Zone 6b with an average last frost of March 29. Plan your Comfrey planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Morris County, NJ?

Morris County, New Jersey is in USDA Hardiness Zone 6b. The average last spring frost is March 29 and first fall frost is November 12.

๐ŸŒฑ

Plan Your Garden with Confidence

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