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When to plant Comfrey in Fields Landing, CA

In Fields Landing, Comfrey is a single-season spring crop — there's no second fall window. Plant March 6–March 20 for an 60–90-day harvest, finishing well before the November 28 first frost.

When to Plant Comfrey in Fields Landing, CA

Humboldt County, California Zone 9b June

Your June game plan for Humboldt County, California

Welcome to June in Zone 9b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost February 27
Avg. first frost November 28
Soil temp (4") 84°F
Watering Critical
Pest pressure High
Daylight 14.9 hrs
  1. Start harvesting comfrey

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Before July arrives, get these ready
  • 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.

Fields Landing, California is in USDA Zone 9b. The average last spring frost is February 27 and the first fall frost is November 28, giving you a growing season of approximately 274 days.

At an elevation of 148 feet, Humboldt County receives approximately 22.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 87°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.

Fields Landing, CA (Zone 9b) Year-round
274 days
Last Spring Frost February 27
274 growing days
First Fall Frost November 28

Fields Landing Soil Profile

Soil Type

Sandy Loam

Soil pH

6.2-6.8

Drainage

Well Drained

Comfrey Planting Risk Windows

Early Start (70% safe) ✓ Fits season (143 days to spare)
Transplant: Feb 20 🍅 Harvest: Apr 24 – Jul 3
Recommended (50%) ✓ Fits season (134 days to spare)
Transplant: Mar 6 🍅 Harvest: May 8 – Jul 17
Safe Start (90%) ✓ Fits season (120 days to spare)
Transplant: Apr 9 🍅 Harvest: Jun 11 – Aug 20

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 Fields Landing

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

Soil pH

Your soil pH (6.2–6.8) is within Comfrey's preferred range (6.0–7.0).

Soil Texture

Sandy soil in Humboldt County warms quickly in spring but drains fast. Comfrey will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is moderate (2.3%). 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 274-day season

Sow every 6.9 weeks. Last sowing by Aug 30 to harvest before frost.

Comfrey Water Budget

Plant needs
1.0″/week
Rainfall provides
0.3″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,621 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 4.8" 0" ❄️ Dormant
Feb 4.3" 5" 0" ✅ Rainfall sufficient
Mar 4.3" 3.3" 1" 💧 Light watering
Apr 4.3" 1.7" 2.6" 🚿 Regular watering
May 4.3" 0.5" 3.8" 🚿 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" 0.3" 4" 🚿 Regular watering
Oct 4.3" 0.8" 3.5" 🚿 Regular watering
Nov 4.3" 1.9" 2.4" 🚿 Regular watering
Dec 3.7" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Humboldt 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 ~1,144 GDD — county provides 4,193 GDD Excellent fit

Comfrey Planting Timeline — Fields Landing, CA

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors March 6 Mar 6 – Mar 20
Harvest May 8 May 8 – Jul 17

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

1"/week · 1-2 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 9b

📆 Growing Season

274 days in Humboldt County

Growing Tips for Comfrey in Fields Landing

Direct sow Comfrey outdoors after February 27 in Humboldt County when soil has warmed and frost danger has passed.

Sandy soil in Humboldt County dries quickly — mulch Comfrey with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Humboldt County receives only 22" 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 →

When should I plant Comfrey in Fields Landing, CA?

In Fields Landing, CA, plant Comfrey after the last frost (around February 27) and before the first frost (around November 28). Best results when soil holds above 50°F.

What growing zone is Fields Landing, CA for Comfrey?

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

Can Comfrey grow in Fields Landing's climate?

Yes — Comfrey grows well in Fields Landing's temperate climate. Fields Landing averages a 275-day frost-free season, with last frost around February 27 and first frost around November 28.

🌱

Your Humboldt County Garden Planner — Free

A 22-page printable planner built for Humboldt County (Zone 9b). 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 Humboldt County, CA. Local conditions may vary. Last updated: June 2026.