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When to Plant Horehound in Petersburg Borough, AK

Horehound is a woolly, drought-tolerant perennial herb traditionally used for cough remedies and candy. It has a distinctive bitter, menthol-like flavor.

Petersburg Borough, Alaska is in USDA Zone 7a. The average last spring frost is April 23 and the first fall frost is October 20, giving you a growing season of approximately 180 days.

At an elevation of 974 feet, Petersburg Borough receives approximately 17.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 57ยฐF, so choose short-season varieties of Horehound to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Horehound successfully. Mulch heavily to conserve soil moisture.

Petersburg Borough, AK (Zone 7a) Moderate season
180 days
Last Spring Frost April 23
180 growing days
First Fall Frost October 20

Petersburg Borough Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (36 days to spare)
Transplant: Apr 23 🍅 Harvest: Jul 9 – Sep 3
Recommended (50%) ✓ Fits season (40 days to spare)
Transplant: Apr 30 🍅 Harvest: Jul 16 – Sep 10
Safe Start (90%) ✓ Fits season (41 days to spare)
Transplant: May 19 🍅 Harvest: Aug 4 – Sep 29

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
0.5″/week
Rainfall provides
0.4″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Horehound needs ~0 GDD — county provides 0 GDD May not mature

Horehound Planting Timeline โ€” Petersburg Borough, AK

Horehound Planting Calendar

Activity When Date Range
Transplant Outdoors April 30 Apr 30 โ€“ May 14
Harvest July 16 Jul 16 โ€“ Sep 10

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

75โ€“90 days

Soil pH

6 โ€“ 8

USDA Zone

Zone 7a

Growing Season

180 days

Growing Tips for Petersburg Borough

Direct sow or start from divisions. Thrives in poor, dry soil. Harvest stems just before flowering. Deadhead to prevent aggressive self-seeding. Very drought-tolerant once established.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Horehound in Petersburg Borough, AK?

Petersburg Borough is in Zone 7a with an average last frost of April 23. Plan your Horehound planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Petersburg Borough, AK?

Petersburg Borough, Alaska is in USDA Hardiness Zone 7a. The average last spring frost is April 23 and first fall frost is October 20.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Petersburg Borough gardeners in Zone 7a 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 Petersburg Borough, AK. Local conditions may vary. Last updated: April 2026.