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When to Plant Comfrey in Anchorage Municipality, AK

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

Anchorage Municipality, Alaska is in USDA Zone 4b. The average last spring frost is May 15 and the first fall frost is September 19, giving you a growing season of approximately 127 days.

At an elevation of 2,537 feet, Anchorage Municipality receives approximately 20.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 71ยฐF, so choose short-season varieties of Comfrey to ensure they mature before fall.

Anchorage Municipality, AK (Zone 4b) Short season
127 days
Last Spring Frost May 15
127 growing days
First Fall Frost September 19

Anchorage Municipality Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 11 🍅 Harvest: Jul 13 – Sep 21
Recommended (50%) ✗ May not fit
Transplant: May 22 🍅 Harvest: Jul 24 – Oct 2
Safe Start (90%) ✗ May not fit
Transplant: Jun 9 🍅 Harvest: Aug 11 – Oct 20

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
0.0″/week
Watering frequency Only during dry spells
Season total 29 gal / 100 sq ft
Comfrey needs ~244 GDD — county provides 412 GDD Excellent fit

Comfrey Planting Timeline โ€” Anchorage Municipality, AK

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors May 22 May 22 โ€“ Jun 5
Harvest July 24 Jul 24 โ€“ Oct 2

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 4b

Growing Season

127 days

Growing Tips for Anchorage Municipality

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 Anchorage Municipality, AK?

Anchorage Municipality is in Zone 4b with an average last frost of May 15. Plan your Comfrey planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Anchorage Municipality, AK?

Anchorage Municipality, Alaska is in USDA Hardiness Zone 4b. The average last spring frost is May 15 and first fall frost is September 19.

๐ŸŒฑ

Plan Your Garden with Confidence

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

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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 Anchorage Municipality, AK. Local conditions may vary. Last updated: April 2026.