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When to Plant Horehound in Chouteau County, MT

Chouteau County, Montana Zone 4a May

May to-do list for Chouteau County, Montana

May is a pivotal month for Chouteau County, Montana gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 12
Avg. first frost September 27
Soil temp (4") 37°F
Watering High
Pest pressure Low
Daylight 14.9 hrs
  1. Transplant horehound outside

    Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.

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

Chouteau County, Montana is in USDA Zone 4a. The average last spring frost is May 12 and the first fall frost is September 27, giving you a growing season of approximately 138 days.

At an elevation of 5,753 feet, Chouteau County receives approximately 15 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, 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.

Chouteau County, MT (Zone 4a) Short season
138 days
Last Spring Frost May 12
138 growing days
First Fall Frost September 27

Chouteau County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 15 🍅 Harvest: Jul 31 – Sep 25
Recommended (50%) ✗ May not fit
Transplant: May 19 🍅 Harvest: Aug 4 – Sep 29
Safe Start (90%) ✗ May not fit
Transplant: Jun 9 🍅 Harvest: Aug 25 – 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.

Soil Compatibility in Chouteau County

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

Soil pH

Your soil pH (6.4–7.8) is within Horehound's preferred range (6.0–8.0).

Soil Texture

The loam soil in Chouteau County is excellent for Horehound — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Horehound.

How to Plant Horehound

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

Succession Planting Horehound

2
successive plantings in your 138-day season

Sow every 8.6 weeks. Last sowing by Jun 29 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 64 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 1" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.4" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 2.2" 1.7" 0.5" 💧 Light watering
Jun 2.2" 1.2" 1" 💧 Light watering
Jul 2.2" 1.4" 0.8" 💧 Light watering
Aug 2.2" 1.8" 0.4" 💧 Light watering
Sep 2.2" 1.1" 1.1" 🚿 Regular watering
Oct 1.2" 0" ❄️ Dormant
Nov 0.9" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Chouteau County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~1,072 GDD — county provides 1,794 GDD Excellent fit

Horehound Planting Timeline — Chouteau County, MT

Horehound Planting Calendar

Activity When Date Range
Transplant Outdoors May 19 May 19 – Jun 2
Harvest August 4 Aug 4 – Sep 29

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

75–90 days

🧪 Soil pH

Needs 6–8 · Your soil: ideal

🗺️ USDA Zone

Zone 4a

📆 Growing Season

138 days in Chouteau County

Growing Tips for Horehound in Chouteau County

Direct sow Horehound outdoors after May 12 in Chouteau County when soil has warmed and frost danger has passed.

Chouteau County receives only 15" of rain annually. Horehound needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Chouteau County, MT?

Chouteau County is in Zone 4a with an average last frost of May 12. Plan your Horehound planting based on this frost date — see the calendar above for exact timing.

What planting zone is Chouteau County, MT?

Chouteau County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is May 12 and first fall frost is September 27.

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Your Chouteau County Garden Planner — Free

A 24-page printable planner built for Chouteau County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Chouteau County, MT. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.