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When to Plant Comfrey in Weston County, WY

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

Weston County, Wyoming is in USDA Zone 4a. The average last spring frost is May 16 and the first fall frost is September 26, giving you a growing season of approximately 133 days.

At an elevation of 5,889 feet, Weston County receives approximately 20.7 inches of rainfall annually with predominantly loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Comfrey to ensure they mature before fall.

Weston County, WY (Zone 4a) Short season
133 days
Last Spring Frost May 16
133 growing days
First Fall Frost September 26

Weston County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 19 🍅 Harvest: Jul 21 – Sep 29
Recommended (50%) ✗ May not fit
Transplant: May 23 🍅 Harvest: Jul 25 – Oct 3
Safe Start (90%) ✗ May not fit
Transplant: Jun 5 🍅 Harvest: Aug 7 – Oct 16

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 492 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Comfrey needs ~806 GDD — county provides 1,429 GDD Excellent fit

Comfrey Planting Timeline โ€” Weston County, WY

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors May 23 May 23 โ€“ Jun 6
Harvest July 25 Jul 25 โ€“ Oct 3

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Transplant Outdoors
June Transplant Outdoors
July Harvest
August Harvest
September Harvest
October Harvest
November โ€”
December โ€”

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“90 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4a

Growing Season

133 days

Growing Tips for Weston 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Comfrey in Weston County, WY?

Weston County is in Zone 4a with an average last frost of May 16. Plan your Comfrey planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Weston County, WY?

Weston County, Wyoming is in USDA Hardiness Zone 4a. The average last spring frost is May 16 and first fall frost is September 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Weston County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

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Free download. Plan your entire garden season in minutes.

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