When to Plant Horehound in Campbell County, TN
Your May gardening checklist
Your Campbell County, Tennessee garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
Horehound is a woolly, drought-tolerant perennial herb traditionally used for cough remedies and candy. It has a distinctive bitter, menthol-like flavor.
Campbell County, Tennessee is in USDA Zone 7a. The average last spring frost is April 11 and the first fall frost is October 25, giving you a growing season of approximately 197 days.
At an elevation of 2,606 feet, Campbell County receives approximately 43.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Horehound during the growing season.
Campbell County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-7.1
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 Campbell County
How your county's soil matches Horehound's growing requirements.
Soil pH
Your soil pH (5.7–7.1) overlaps with Horehound's range (6.0–8.0), though not a perfect match.
Soil Texture
The silt loam soil in Campbell County is excellent for Horehound — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.1%). Annual compost additions will help Horehound.
How to Plant Horehound
Succession Planting Horehound
Sow every 8.6 weeks. Last sowing by Jul 27 to harvest before frost.
Plant Water Budget
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 | — | 4" | 0" | ❄️ Dormant |
| Feb | — | 3.6" | 0" | ❄️ Dormant |
| Mar | — | 4.1" | 0" | ❄️ Dormant |
| Apr | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.5" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Nov | — | 3.2" | 0" | ❄️ Dormant |
| Dec | — | 3.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Campbell 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 — Campbell County, TN
Horehound Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 18 | Apr 18 – May 2 |
| Harvest | July 4 | Jul 4 – Aug 29 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Harvest |
| September | — |
| 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 7a
📆 Growing Season
197 days in Campbell County
Growing Tips for Horehound in Campbell County
Direct sow Horehound outdoors after April 11 in Campbell 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 Campbell County, TN?
Campbell County is in Zone 7a with an average last frost of April 11. Plan your Horehound planting based on this frost date — see the calendar above for exact timing.
What planting zone is Campbell County, TN?
Campbell County, Tennessee is in USDA Hardiness Zone 7a. The average last spring frost is April 11 and first fall frost is October 25.
Your Campbell County Garden Planner — Free
A 24-page printable planner built for Campbell County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.