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When to plant Comfrey in Occidental, CA

In Occidental, Comfrey is a single-season spring crop — there's no second fall window. Plant March 5–March 19 for an 60–90-day harvest, finishing well before the November 26 first frost.

When to Plant Comfrey in Occidental, CA

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

Occidental, California is in USDA Zone 9b. The average last spring frost is February 26 and the first fall frost is November 26, giving you a growing season of approximately 273 days.

At an elevation of 91 feet, Sonoma County receives approximately 31.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 90°F, providing good warmth for Comfrey during the growing season. Sandy soil warms quickly in spring — great for early planting — but Comfrey will need more frequent watering and organic matter to retain nutrients.

Occidental, CA (Zone 9b) Year-round
273 days
Last Spring Frost February 26
273 growing days
First Fall Frost November 26

Occidental Soil Profile

Soil Type

Sandy Loam

Soil pH

5.9-7

Drainage

Well Drained

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 6.2" 0" ❄️ Dormant
Feb 4.3" 6.8" 0" ✅ Rainfall sufficient
Mar 4.3" 5.2" 0" ✅ Rainfall sufficient
Apr 4.3" 2.3" 2" 💧 Light watering
May 4.3" 0.8" 3.5" 🚿 Regular watering
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 4.3" 0.4" 3.9" 🚿 Regular watering
Oct 4.3" 1.3" 3" 🚿 Regular watering
Nov 4.3" 2.7" 1.6" 💧 Light watering
Dec 5.2" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Sonoma County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Comfrey Planting Timeline — Occidental, CA

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors March 5 Mar 5 – Mar 19
Harvest May 7 May 7 – Jul 16

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 9b

📆 Growing Season

273 days in Sonoma County

Growing Tips for Occidental

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 →

When should I plant Comfrey in Occidental, CA?

In Occidental, CA, plant Comfrey after the last frost (around February 26) and before the first frost (around November 26). Best results when soil holds above 50°F.

What growing zone is Occidental, CA for Comfrey?

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

Can Comfrey grow in Occidental's climate?

Yes — Comfrey grows well in Occidental's temperate climate. Occidental averages a 274-day frost-free season, with last frost around February 26 and first frost around November 26.

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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 Sonoma County, CA. Local conditions may vary. Last updated: July 2026.