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When to plant Comfrey in Alpine County, CA

Plant Comfrey in Alpine County, between May 26 and June 9 — the only viable window. Zone 6b's short season (137 frost-free days) rules out a fall crop.

When to Plant Comfrey in Alpine County, CA

Alpine County, California Zone 6b July

Your July gardening checklist

If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 19
Avg. first frost October 3
Soil temp (4") 77°F
Watering Critical
Pest pressure High
Daylight 14.4 hrs
  1. Start harvesting comfrey

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Looking ahead to August
  • First harvests: comfrey

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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.

Alpine County, California is in USDA Zone 6b. The average last spring frost is May 19 and the first fall frost is October 3, giving you a growing season of approximately 137 days.

At an elevation of 1,278 feet, Alpine County receives approximately 36.3 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.

Alpine County, CA (Zone 6b) Short season
137 days
Last Spring Frost May 19
137 growing days
First Fall Frost October 3

Alpine County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.3

Drainage

Well Drained

Comfrey Planting Risk Windows

Early Start (70% safe) ✓ Fits season (4 days to spare)
Transplant: May 10 🍅 Harvest: Jul 12 – Sep 20
Recommended (50%) ✗ May not fit
Transplant: May 26 🍅 Harvest: Jul 28 – Oct 6
Safe Start (90%) ✗ May not fit
Transplant: Jun 17 🍅 Harvest: Aug 19 – Oct 28

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 Alpine County

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

Soil pH

Your soil pH (6.4–7.3) overlaps with Comfrey's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.2%). Annual compost additions will help Comfrey.

How to Plant Comfrey

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

Succession Planting Comfrey

2
successive plantings in your 137-day season

Sow every 6.9 weeks. Last sowing by Jul 05 to harvest before frost.

Comfrey Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 7.1" 0" ❄️ Dormant
Feb 8.7" 0" ❄️ Dormant
Mar 5.7" 0" ❄️ Dormant
Apr 2.7" 0" ❄️ Dormant
May 4.3" 1" 3.3" 🚿 Regular watering
Jun 4.3" 0.2" 4.1" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.3" 4" 🚿 Regular watering
Oct 4.3" 1.6" 2.7" 🚿 Regular watering
Nov 3.7" 0" ❄️ Dormant
Dec 5.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Alpine 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 1,781 GDD Excellent fit

Comfrey Planting Timeline — Alpine County, CA

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors May 26 May 26 – Jun 9
Harvest July 28 Jul 28 – Oct 6

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

137 days in Alpine County

Growing Tips for Comfrey in Alpine County

Direct sow Comfrey outdoors after May 19 in Alpine 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 Alpine County, CA?

Alpine County is in Zone 6b with an average last frost of May 19. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.

What planting zone is Alpine County, CA?

Alpine County, California is in USDA Hardiness Zone 6b. The average last spring frost is May 19 and first fall frost is October 3.

When should I plant Comfrey in Alpine County, CA?

In Alpine County, CA, plant Comfrey after the last frost (around May 19) and before the first frost (around October 3). Best results when soil holds above 50°F.

What growing zone is Alpine County, CA for Comfrey?

Alpine 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 Alpine County's climate?

Yes — Comfrey grows well in Alpine County's temperate climate. Alpine County averages a 137-day frost-free season, with last frost around May 19 and first frost around October 3.

🌱

Your Alpine County Garden Planner — Free

A 22-page printable planner built for Alpine 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 Alpine County, CA. Local conditions may vary. Last updated: July 2026.

Sources & credits

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