When to Plant Horehound in Missoula County, MT
Missoula County, Montana gardeners: here's your May plan
Here's what deserves your attention in Missoula County, Montana this month. Everything below is tailored to Zone 5b and timed around your local frost dates.
-
Move horehound into the garden
Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.
Horehound is a woolly, drought-tolerant perennial herb traditionally used for cough remedies and candy. It has a distinctive bitter, menthol-like flavor.
Missoula County, Montana is in USDA Zone 5b. The average last spring frost is May 14 and the first fall frost is September 23, giving you a growing season of approximately 132 days.
At an elevation of 8,019 feet, Missoula County receives approximately 15.9 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Horehound during the growing season. With low rainfall, drip irrigation is essential for growing Horehound successfully. Mulch heavily to conserve soil moisture.
Missoula County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.7
Drainage
Well Drained
Plant Planting Risk Windows
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 Missoula County
How your county's soil matches Horehound's growing requirements.
Soil pH
Your soil pH (6.2–7.7) is within Horehound's preferred range (6.0–8.0).
Soil Texture
The loam soil in Missoula County is excellent for Horehound — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Horehound.
How to Plant Horehound
Plant Water Budget
Water stress score is 8/10 — 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 | — | 1.6" | 0" | ❄️ Dormant |
| Apr | — | 1.7" | 0" | ❄️ Dormant |
| May | 2.2" | 1.7" | 0.5" | 💧 Light watering |
| Jun | 2.2" | 1.1" | 1.1" | 🚿 Regular watering |
| Jul | 2.2" | 1.3" | 0.9" | 💧 Light watering |
| Aug | 2.2" | 1.9" | 0.3" | 💧 Light watering |
| Sep | 2.2" | 1.4" | 0.8" | 💧 Light watering |
| Oct | — | 1.5" | 0" | ❄️ Dormant |
| Nov | — | 1" | 0" | ❄️ Dormant |
| Dec | — | 1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Missoula 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 Planting Timeline — Missoula County, MT
Horehound Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 21 | May 21 – Jun 4 |
| Harvest | August 6 | Aug 6 – Oct 1 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | Transplant Outdoors |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
75–90 days
🧪 Soil pH
Needs 6–8 · Your soil: ideal
🗺️ USDA Zone
Zone 5b
📆 Growing Season
132 days in Missoula County
Growing Tips for Horehound in Missoula County
Direct sow Horehound outdoors after May 14 in Missoula County when soil has warmed and frost danger has passed.
Missoula County receives only 16" 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 →
Horehound in Other Locations
Frequently Asked Questions
When should I plant Horehound in Missoula County, MT?
Missoula County is in Zone 5b with an average last frost of May 14. Plan your Horehound planting based on this frost date — see the calendar above for exact timing.
What planting zone is Missoula County, MT?
Missoula County, Montana is in USDA Hardiness Zone 5b. The average last spring frost is May 14 and first fall frost is September 23.
Your Missoula County Garden Planner — Free
A 24-page printable planner built for Missoula County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.