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When to Plant Comfrey in Broadbent, OR

Coos County, Oregon Zone 9a June

Coos County, Oregon gardeners: here's your June plan

Here's what deserves your attention in Coos County, Oregon this month. Everything below is tailored to Zone 9a and timed around your local frost dates.

Avg. last frost March 22
Avg. first frost November 19
Soil temp (4") 81°F
Watering High
Pest pressure High
Daylight 15.2 hrs
  1. Collect comfrey at their peak

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

Coming up in July — start thinking about
  • 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.

Broadbent, Oregon is in USDA Zone 9a. The average last spring frost is March 22 and the first fall frost is November 19, giving you a growing season of approximately 242 days.

At an elevation of 96 feet, Coos County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Comfrey during the growing season.

Broadbent, OR (Zone 9a) Long season
242 days
Last Spring Frost March 22
242 growing days
First Fall Frost November 19

Broadbent Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Comfrey Planting Risk Windows

Early Start (70% safe) ✓ Fits season (99 days to spare)
Transplant: Mar 14 🍅 Harvest: May 16 – Jul 25
Recommended (50%) ✓ Fits season (102 days to spare)
Transplant: Mar 29 🍅 Harvest: May 31 – Aug 9
Safe Start (90%) ✓ Fits season (97 days to spare)
Transplant: Apr 29 🍅 Harvest: Jul 1 – Sep 9

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 Broadbent

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

Soil pH

Your soil pH (5.4–6.8) overlaps with Comfrey's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.7%) — Comfrey will thrive.

How to Plant Comfrey

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

Succession Planting Comfrey

4
successive plantings in your 242-day season

Sow every 6.9 weeks. Last sowing by Aug 21 to harvest before frost.

Comfrey Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 703 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 5.5" 0" ❄️ Dormant
Feb 4.5" 0" ❄️ Dormant
Mar 4.3" 4.4" 0" ✅ Rainfall sufficient
Apr 4.3" 3.1" 1.2" 💧 Light watering
May 4.3" 2.3" 2" 💧 Light watering
Jun 4.3" 1.6" 2.7" 🚿 Regular watering
Jul 4.3" 0.6" 3.7" 🚿 Regular watering
Aug 4.3" 0.8" 3.5" 🚿 Regular watering
Sep 4.3" 1.4" 2.9" 🚿 Regular watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 4.3" 5.9" 0" ✅ Rainfall sufficient
Dec 5.5" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Coos 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 ~1,256 GDD — county provides 4,053 GDD Excellent fit

Comfrey Planting Timeline — Broadbent, OR

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors March 29 Mar 29 – Apr 12
Harvest May 31 May 31 – Aug 9

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

Month-by-Month Timeline

MonthActivities
January
February
March Transplant Outdoors
April Transplant Outdoors
May Harvest
June Harvest
July Harvest
August Harvest
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: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

242 days in Coos County

Growing Tips for Comfrey in Broadbent

Direct sow Comfrey outdoors after March 22 in Coos 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 →

🌱

Your Coos County Garden Planner — Free

A 22-page printable planner built for Coos County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Coos County, OR. Local conditions may vary. Last updated: June 2026.