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When to plant Comfrey in Rosebud County, MT

Plant Comfrey in Rosebud County during the brief May 18–June 1 window. With 145 frost-free days, fall plantings can't mature before October 3.

When to Plant Comfrey in Rosebud 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.

Rosebud County, Montana is in USDA Zone 4b. The average last spring frost is May 11 and the first fall frost is October 3, giving you a growing season of approximately 145 days.

At an elevation of 6,448 feet, Rosebud County receives approximately 22.8 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.

Rosebud County, MT (Zone 4b) Short season
145 days
Last Spring Frost May 11
145 growing days
First Fall Frost October 3

Rosebud County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Comfrey Planting Timeline — Rosebud County, MT

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors May 18 May 18 – Jun 1
Harvest July 20 Jul 20 – Sep 28

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
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

145 days in Rosebud County

Growing Tips for Rosebud 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 Rosebud County, MT?

Rosebud County is in Zone 4b with an average last frost of May 11. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.

What planting zone is Rosebud County, MT?

Rosebud County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 11 and first fall frost is October 3.

When should I plant Comfrey in Rosebud County, MT?

In Rosebud County, MT, plant Comfrey after the last frost (around May 11) and before the first frost (around October 3). Best results when soil holds above 50°F.

What growing zone is Rosebud County, MT for Comfrey?

Rosebud 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 Rosebud County's climate?

Yes — Comfrey grows well in Rosebud County's temperate climate. Rosebud County averages a 145-day frost-free season, with last frost around May 11 and first frost around October 3.

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Your Rosebud County Garden Planner — Free

A 22-page printable planner built for Rosebud 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 Rosebud County, MT. Local conditions may vary. Last updated: July 2026.

Sources & credits

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