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When to Plant Comfrey in Prince William County, VA

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

Prince William County, Virginia is in USDA Zone 7a. The average last spring frost is April 13 and the first fall frost is October 26, giving you a growing season of approximately 196 days.

At an elevation of 372 feet, Prince William County receives approximately 46.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Comfrey during the growing season.

Prince William County, VA (Zone 7a) Moderate season
196 days
Last Spring Frost April 13
196 growing days
First Fall Frost October 26

Prince William County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (60 days to spare)
Transplant: Apr 8 🍅 Harvest: Jun 10 – Aug 19
Recommended (50%) ✓ Fits season (56 days to spare)
Transplant: Apr 20 🍅 Harvest: Jun 22 – Aug 31
Safe Start (90%) ✓ Fits season (59 days to spare)
Transplant: May 15 🍅 Harvest: Jul 17 – Sep 25

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
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 17 gal / 100 sq ft
Comfrey needs ~1,256 GDD — county provides 3,283 GDD Excellent fit

Comfrey Planting Timeline โ€” Prince William County, VA

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 7a

Growing Season

196 days

Growing Tips for Prince William 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 Prince William County, VA?

Prince William County is in Zone 7a 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 Prince William County, VA?

Prince William County, Virginia is in USDA Hardiness Zone 7a. The average last spring frost is April 13 and first fall frost is October 26.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Prince William County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.

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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 Prince William County, VA. Local conditions may vary. Last updated: April 2026.