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When to plant Comfrey in Howe, ID

In Howe, Comfrey is a spring-only crop. Plant June 8–June 22 once soil hits 50°F.

When to Plant Comfrey in Howe, ID

Butte County, Idaho Zone 5a 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 June 1
Avg. first frost September 14
Soil temp (4") 50°F
Watering High
Pest pressure High
Daylight 14.9 hrs
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.

Howe, Idaho is in USDA Zone 5a. The average last spring frost is June 1 and the first fall frost is September 14, giving you a growing season of approximately 105 days.

At an elevation of 7,254 feet, Butte County receives approximately 24 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.

Howe, ID (Zone 5a) Short season
105 days
Last Spring Frost June 1
105 growing days
First Fall Frost September 14

Howe Soil Profile

Soil Type

Loam

Soil pH

6.8-8.4

Drainage

Well Drained

Comfrey Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 28 🍅 Harvest: Jul 30 – Oct 8
Recommended (50%) ✗ May not fit
Transplant: Jun 8 🍅 Harvest: Aug 10 – Oct 19
Safe Start (90%) ✗ May not fit
Transplant: Jun 24 🍅 Harvest: Aug 26 – Nov 4

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 Howe

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

Soil pH

Your soil pH (6.8–8.4) is more alkaline than Comfrey prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). 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
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 45 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 1.8" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 3" 0" ❄️ Dormant
Jun 4.3" 1.9" 2.4" 🚿 Regular watering
Jul 4.3" 1.9" 2.4" 🚿 Regular watering
Aug 4.3" 2.7" 1.6" 💧 Light watering
Sep 4.3" 1.7" 2.6" 🚿 Regular watering
Oct 2.2" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Butte 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 1,365 GDD Excellent fit

Comfrey Planting Timeline — Howe, ID

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors June 8 Jun 8 – Jun 22
Harvest August 10 Aug 10 – Oct 19

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 5a

📆 Growing Season

105 days in Butte County

Growing Tips for Comfrey in Howe

Direct sow Comfrey outdoors after June 01 in Butte County when soil has warmed and frost danger has passed.

Butte County receives only 24" 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 Howe, ID?

In Howe, ID, plant Comfrey after the last frost (around June 1) and before the first frost (around September 14). Best results when soil holds above 50°F.

What growing zone is Howe, ID for Comfrey?

Howe sits in USDA Zone 5a. Comfrey grows reliably in zones 3a through 9b, so it's a good fit here.

Can Comfrey grow in Howe's climate?

Yes — Comfrey grows well in Howe's temperate climate. Howe averages a 105-day frost-free season, with last frost around June 1 and first frost around September 14.

🌱

Your Butte County Garden Planner — Free

A 22-page printable planner built for Butte County (Zone 5a). 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 Butte County, ID. Local conditions may vary. Last updated: July 2026.