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When to Plant Horehound in Clarke County, IA

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

Clarke County, Iowa is in USDA Zone 5a. The average last spring frost is April 24 and the first fall frost is October 11, giving you a growing season of approximately 170 days.

At an elevation of 1,182 feet, Clarke County receives approximately 35.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Horehound during the growing season.

Clarke County, IA (Zone 5a) Moderate season
170 days
Last Spring Frost April 24
170 growing days
First Fall Frost October 11

Clarke County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.9

Drainage

Well Drained

Monthly Watering Guide for Horehound

Horehound needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Horehound Needs Rainfall You Supplement Action
Jan โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.7" 0" โ„๏ธ Dormant
Mar โ€” 2.2" 0" โ„๏ธ Dormant
Apr 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
May 4.3" 4.5" 0" โœ… Rainfall sufficient
Jun 4.3" 4" 0.3" ๐Ÿ’ง Light watering
Jul 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Aug 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Sep 4.3" 3.2" 1.1" ๐Ÿ’ง Light watering
Oct 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Nov โ€” 2.3" 0" โ„๏ธ Dormant
Dec โ€” 2.2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Clarke County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Horehound Planting Timeline โ€” Clarke County, IA

Horehound Planting Calendar

Activity When Date Range
Transplant Outdoors May 1 May 1 โ€“ May 15
Harvest July 17 Jul 17 โ€“ Sep 11

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 โ€”
July Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

Low โ€” drought tolerant

๐Ÿ“… Days to Maturity

75โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“8 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

170 days in Clarke County

Growing Tips for Clarke County

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Horehound in Clarke County, IA?

Clarke County is in Zone 5a with an average last frost of April 24. Plan your Horehound planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Clarke County, IA?

Clarke County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 24 and first fall frost is October 11.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Clarke County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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 Clarke County, IA. Local conditions may vary. Last updated: April 2026.