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When to plant Comfrey in Mono County, CA

Mono County sits in cold Zone 6b. Plant Comfrey June 25–July 9 for the single annual harvest; the August 20 first frost closes the window.

When to Plant Comfrey in Mono County, CA

Mono County, California Zone 6b June

June in Mono County, California — your action list

We've pulled the most time-sensitive tasks for Mono County, California this June and put them front and centre. Tackle them in order.

Avg. last frost June 18
Avg. first frost August 20
Soil temp (4") 65°F
Watering Critical
Pest pressure High
Daylight 14.6 hrs
  1. Move comfrey from tray to bed

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

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

Mono County, California is in USDA Zone 6b. The average last spring frost is June 18 and the first fall frost is August 20, giving you a growing season of approximately 63 days.

At an elevation of 2,381 feet, Mono County receives approximately 13.3 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Comfrey to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Comfrey successfully. Mulch heavily to conserve soil moisture.

Mono County, CA (Zone 6b) Very short season
63 days
Last Spring Frost June 18
63 growing days
First Fall Frost August 20

Mono County Soil Profile

Soil Type

Loam

Soil pH

6-7.5

Drainage

Well Drained

Comfrey Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 29 🍅 Harvest: Jul 31 – Oct 9
Recommended (50%) ✗ May not fit
Transplant: Jun 25 🍅 Harvest: Aug 27 – Nov 5
Safe Start (90%) ✗ May not fit
Transplant: Jul 7 🍅 Harvest: Sep 8 – Nov 17

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 Mono County

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

Soil pH

Your soil pH (6.0–7.5) overlaps with Comfrey's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in Mono County is excellent for Comfrey — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Comfrey.

How to Plant Comfrey

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

Comfrey Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 76 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 2.7" 0" ❄️ Dormant
Feb 3.1" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 1" 0" ❄️ Dormant
May 0.3" 0" ❄️ Dormant
Jun 4.3" 0.1" 4.2" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 0.2" 0" ❄️ Dormant
Oct 0.6" 0" ❄️ Dormant
Nov 1.1" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Aug in Mono County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~975 GDD — county provides 819 GDD May not mature

Comfrey Planting Timeline — Mono County, CA

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors June 25 Jun 25 – Jul 9
Harvest August 27 Aug 27 – Nov 5

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

63 days in Mono County

Growing Tips for Comfrey in Mono County

Direct sow Comfrey outdoors after June 18 in Mono County when soil has warmed and frost danger has passed.

Your 63.0-day growing season in Mono County is tight for Comfrey (60.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.

Mono County receives only 13" of rain annually. Comfrey needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Mono County, CA?

Mono County is in Zone 6b with an average last frost of June 18. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mono County, CA?

Mono County, California is in USDA Hardiness Zone 6b. The average last spring frost is June 18 and first fall frost is August 20.

When should I plant Comfrey in Mono County, CA?

In Mono County, CA, plant Comfrey after the last frost (around June 18) and before the first frost (around August 20). Best results when soil holds above 50°F.

What growing zone is Mono County, CA for Comfrey?

Mono County sits in USDA Zone 6b. Comfrey grows reliably in zones 3a through 9b, so it's a good fit here.

Can Comfrey grow in Mono County's climate?

Yes — Comfrey grows well in Mono County's temperate climate. Mono County averages a 63-day frost-free season, with last frost around June 18 and first frost around August 20.

🌱

Your Mono County Garden Planner — Free

A 22-page printable planner built for Mono County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Mono County, CA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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