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When to Plant Horehound in Cook County, MN

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

Cook County, Minnesota is in USDA Zone 3a. The average last spring frost is May 20 and the first fall frost is September 29, giving you a growing season of approximately 132 days.

At an elevation of 1,068 feet, Cook County receives approximately 34.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Horehound to ensure they mature before fall.

Cook County, MN (Zone 3a) Short season
132 days
Last Spring Frost May 20
132 growing days
First Fall Frost September 29

Cook County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 22 🍅 Harvest: Aug 7 – Sep 25
Recommended (50%) ✗ May not fit
Transplant: May 27 🍅 Harvest: Aug 12 – Sep 30
Safe Start (90%) ✓ Fits season (2 days to spare)
Transplant: Jun 7 🍅 Harvest: Aug 23 – Oct 11

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.

Soil Compatibility in Cook County

How your county's soil matches Horehound's growing requirements.

Soil pH

Your soil pH (6.1โ€“7.1) is within Horehound's preferred range (6.0โ€“8.0).

Soil Texture

The silt loam soil in Cook County is excellent for Horehound โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.4%) โ€” Horehound will thrive.

How to Plant Horehound

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Horehound

Horehound needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Horehound Needs Rainfall You Supplement Action
Jan โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 2.5" 0" โ„๏ธ Dormant
Apr โ€” 3.5" 0" โ„๏ธ Dormant
May 2.2" 3.4" 0" โœ… Rainfall sufficient
Jun 2.2" 4.7" 0" โœ… Rainfall sufficient
Jul 2.2" 3.9" 0" โœ… Rainfall sufficient
Aug 2.2" 3" 0" โœ… Rainfall sufficient
Sep 2.2" 3.2" 0" โœ… Rainfall sufficient
Oct โ€” 2.7" 0" โ„๏ธ Dormant
Nov โ€” 2.5" 0" โ„๏ธ Dormant
Dec โ€” 2" 0" โ„๏ธ Dormant

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

Horehound Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Horehound needs ~825 GDD — county provides 1,320 GDD Excellent fit

Horehound Planting Timeline โ€” Cook County, MN

Horehound Planting Calendar

Activity When Date Range
Transplant Outdoors May 27 May 27 โ€“ Jun 10
Harvest August 12 Aug 12 โ€“ Sep 30

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

75โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“8 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 3a

๐Ÿ“† Growing Season

132 days in Cook County

Growing Tips for Horehound in Cook County

Direct sow Horehound outdoors after May 20 in Cook County when soil has warmed and frost danger has passed.

General growing tips

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 Cook County, MN?

Cook County is in Zone 3a with an average last frost of May 20. Plan your Horehound planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Cook County, MN?

Cook County, Minnesota is in USDA Hardiness Zone 3a. The average last spring frost is May 20 and first fall frost is September 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Cook County gardeners in Zone 3a 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 Cook County, MN. Local conditions may vary. Last updated: April 2026.