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When to plant Comfrey in Cascade County, MT

Cascade County's 125-day season only supports one Comfrey planting per year. Sow between May 26 and June 9 for the best chance at full maturity before September 21.

When to Plant Comfrey in Cascade County, MT

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

Cascade County, Montana is in USDA Zone 4b. The average last spring frost is May 19 and the first fall frost is September 21, giving you a growing season of approximately 125 days.

At an elevation of 6,585 feet, Cascade County receives approximately 21.8 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Comfrey to ensure they mature before fall.

Cascade County, MT (Zone 4b) Short season
125 days
Last Spring Frost May 19
125 growing days
First Fall Frost September 21

Cascade County Soil Profile

Soil Type

Loam

Soil pH

6.8-8.2

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 1.8" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 4.3" 2.3" 2" 💧 Light watering
Jun 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 2.1" 2.2" 🚿 Regular watering
Aug 4.3" 2" 2.3" 🚿 Regular watering
Sep 4.3" 1.8" 2.5" 🚿 Regular watering
Oct 2.1" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

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

Comfrey Planting Timeline — Cascade County, MT

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

Moderate — regular watering

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 4b

📆 Growing Season

125 days in Cascade County

Growing Tips for Cascade County

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 Cascade County, MT?

Cascade County is in Zone 4b 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 Cascade County, MT?

Cascade County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 19 and first fall frost is September 21.

When should I plant Comfrey in Cascade County, MT?

In Cascade County, MT, plant Comfrey after the last frost (around May 19) and before the first frost (around September 21). Best results when soil holds above 50°F.

What growing zone is Cascade County, MT for Comfrey?

Cascade County sits in USDA Zone 4b. Comfrey grows reliably in zones 3a through 9b, so it's a good fit here.

Can Comfrey grow in Cascade County's climate?

Yes — Comfrey grows well in Cascade County's temperate climate. Cascade County averages a 125-day frost-free season, with last frost around May 19 and first frost around September 21.

🌱

Your Cascade County Garden Planner — Free

A 22-page printable planner built for Cascade County (Zone 4b). 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 Cascade County, MT. Local conditions may vary. Last updated: July 2026.

Sources & credits

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