When to Plant Horehound in Marshall 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.
Marshall County, Minnesota is in USDA Zone 3a. The average last spring frost is May 11 and the first fall frost is October 2, giving you a growing season of approximately 144 days.
At an elevation of 1,303 feet, Marshall County receives approximately 33.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Horehound to ensure they mature before fall.
Marshall County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-7.3
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 Marshall County
How your county's soil matches Horehound's growing requirements.
Soil pH
Your soil pH (5.8–7.3) overlaps with Horehound's range (6.0–8.0), though not a perfect match.
Soil Texture
The silt loam soil in Marshall County is excellent for Horehound — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.2%) — Horehound will thrive.
How to Plant Horehound
Succession Planting Horehound
Sow every 8.6 weeks. Last sowing by Jul 04 to harvest before frost.
Plant Water Budget
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 | — | 1.2" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | — | 3.2" | 0" | ❄️ Dormant |
| May | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.6" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.2" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Marshall 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 — Marshall County, MN
Horehound Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 18 | May 18 – Jun 1 |
| Harvest | August 3 | Aug 3 – Sep 21 |
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 | — |
| 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: acceptable
🗺️ USDA Zone
Zone 3a
📆 Growing Season
144 days in Marshall County
Growing Tips for Horehound in Marshall County
Direct sow Horehound outdoors after May 11 in Marshall 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 →
Horehound in Other Locations
Frequently Asked Questions
When should I plant Horehound in Marshall County, MN?
Marshall County is in Zone 3a with an average last frost of May 11. Plan your Horehound planting based on this frost date — see the calendar above for exact timing.
What planting zone is Marshall County, MN?
Marshall County, Minnesota is in USDA Hardiness Zone 3a. The average last spring frost is May 11 and first fall frost is October 2.
Plan Your Garden with Confidence
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