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When to Plant Comfrey in Klamath County, OR

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

Klamath County, Oregon is in USDA Zone 6a. The average last spring frost is June 13 and the first fall frost is September 21, giving you a growing season of approximately 100 days.

At an elevation of 142 feet, Klamath County receives approximately 48.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Comfrey to ensure they mature before fall.

Klamath County, OR (Zone 6a) Short season
100 days
Last Spring Frost June 13
100 growing days
First Fall Frost September 21

Klamath County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Jun 6 🍅 Harvest: Aug 8 – Oct 17
Recommended (50%) ✗ May not fit
Transplant: Jun 20 🍅 Harvest: Aug 22 – Oct 31
Safe Start (90%) ✗ May not fit
Transplant: Jul 3 🍅 Harvest: Sep 4 – Nov 13

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 Klamath County

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

Soil pH

Your soil pH (5.5โ€“6.3) is more acidic than Comfrey prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Comfrey.

Organic Matter

Organic matter is excellent (5.1%) โ€” Comfrey will thrive.

How to Plant Comfrey

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
2.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 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€” 7.4" 0" โ„๏ธ Dormant
Feb โ€” 5.2" 0" โ„๏ธ Dormant
Mar โ€” 4.8" 0" โ„๏ธ Dormant
Apr โ€” 3.3" 0" โ„๏ธ Dormant
May โ€” 3" 0" โ„๏ธ Dormant
Jun 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering
Jul 4.3" 0.9" 3.4" ๐Ÿšฟ Regular watering
Aug 4.3" 0.8" 3.5" ๐Ÿšฟ Regular watering
Sep 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Oct โ€” 4.8" 0" โ„๏ธ Dormant
Nov โ€” 7.7" 0" โ„๏ธ Dormant
Dec โ€” 6.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Sep in Klamath 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 ~919 GDD — county provides 1,225 GDD Excellent fit

Comfrey Planting Timeline โ€” Klamath County, OR

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors June 20 Jun 20 โ€“ Jul 4
Harvest August 22 Aug 22 โ€“ Oct 31

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 โ€”
June Transplant Outdoors
July Transplant Outdoors
August Harvest
September Harvest
October Harvest
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

100 days in Klamath County

Growing Tips for Comfrey in Klamath County

Direct sow Comfrey outdoors after June 13 in Klamath County when soil has warmed and frost danger has passed.

Your 100.0-day growing season in Klamath County is tight for Comfrey (60.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.

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 Klamath County, OR?

Klamath County is in Zone 6a with an average last frost of June 13. Plan your Comfrey planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Klamath County, OR?

Klamath County, Oregon is in USDA Hardiness Zone 6a. The average last spring frost is June 13 and first fall frost is September 21.

๐ŸŒฑ

Plan Your Garden with Confidence

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