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When to Plant Comfrey in Amador County, CA

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

Amador County, California is in USDA Zone 8a. The average last spring frost is March 8 and the first fall frost is November 25, giving you a growing season of approximately 262 days.

At an elevation of 1,335 feet, Amador County receives approximately 42.7 inches of rainfall annually with predominantly loam soil. Summer highs average 89ยฐF, providing good warmth for Comfrey during the growing season.

Amador County, CA (Zone 8a) Long season
262 days
Last Spring Frost March 8
262 growing days
First Fall Frost November 25

Amador County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (137 days to spare)
Transplant: Feb 12 🍅 Harvest: Apr 16 – Jun 25
Recommended (50%) ✓ Fits season (122 days to spare)
Transplant: Mar 15 🍅 Harvest: May 17 – Jul 26
Safe Start (90%) ✓ Fits season (104 days to spare)
Transplant: Apr 26 🍅 Harvest: Jun 28 – Sep 6

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 Amador County

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

Soil pH

Your soil pH (6.7โ€“7.8) is more alkaline than Comfrey prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Comfrey.

How to Plant Comfrey

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

Succession Planting Comfrey

5
successive plantings in your 262-day season

Sow every 6.9 weeks. Last sowing by Aug 27 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 883 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

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€” 9.4" 0" โ„๏ธ Dormant
Feb โ€” 8" 0" โ„๏ธ Dormant
Mar 4.3" 6" 0" โœ… Rainfall sufficient
Apr 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
May 4.3" 1" 3.3" ๐Ÿšฟ Regular watering
Jun 4.3" 0.2" 4.1" ๐Ÿšฟ Regular watering
Jul 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Aug 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Sep 4.3" 0.5" 3.8" ๐Ÿšฟ Regular watering
Oct 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering
Nov 4.3" 4.3" 0" โœ… Rainfall sufficient
Dec โ€” 7.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Amador 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 ~1,256 GDD — county provides 4,388 GDD Excellent fit

Comfrey Planting Timeline โ€” Amador County, CA

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors March 15 Mar 15 โ€“ Mar 29
Harvest May 17 May 17 โ€“ Jul 26

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Transplant Outdoors
April โ€”
May Harvest
June Harvest
July Harvest
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

262 days in Amador County

Growing Tips for Comfrey in Amador County

Direct sow Comfrey outdoors after March 08 in Amador 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 Amador County, CA?

Amador County is in Zone 8a with an average last frost of March 8. Plan your Comfrey planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Amador County, CA?

Amador County, California is in USDA Hardiness Zone 8a. The average last spring frost is March 8 and first fall frost is November 25.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Amador County gardeners in Zone 8a 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 Amador County, CA. Local conditions may vary. Last updated: April 2026.