When to Plant Horehound in Loudoun County, VA
Horehound is a woolly, drought-tolerant perennial herb traditionally used for cough remedies and candy. It has a distinctive bitter, menthol-like flavor.
Loudoun County, Virginia is in USDA Zone 7a. The average last spring frost is April 18 and the first fall frost is October 19, giving you a growing season of approximately 184 days.
At an elevation of 857 feet, Loudoun County receives approximately 45.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 94°F, providing good warmth for Horehound during the growing season.
Loudoun County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-6.5
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 Loudoun County
How your county's soil matches Horehound's growing requirements.
Soil pH
Your soil pH (5.3–6.5) is more acidic than Horehound prefers (6.0–8.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Loudoun County is excellent for Horehound — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Horehound prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.
Organic Matter
Organic matter is moderate (2.8%). Annual compost additions will help Horehound.
How to Plant Horehound
Succession Planting Horehound
Sow every 8.6 weeks. Last sowing by Jul 21 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 | — | 3.5" | 0" | ❄️ Dormant |
| Feb | — | 3.4" | 0" | ❄️ Dormant |
| Mar | — | 4" | 0" | ❄️ Dormant |
| Apr | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.7" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.4" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.6" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Nov | — | 3.5" | 0" | ❄️ Dormant |
| Dec | — | 3.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Loudoun 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 — Loudoun County, VA
Horehound Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 25 | Apr 25 – May 9 |
| Harvest | July 11 | Jul 11 – Sep 5 |
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 | 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: too_acidic
🗺️ USDA Zone
Zone 7a
📆 Growing Season
184 days in Loudoun County
Growing Tips for Horehound in Loudoun County
Direct sow Horehound outdoors after April 18 in Loudoun 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 Loudoun County, VA?
Loudoun County is in Zone 7a with an average last frost of April 18. Plan your Horehound planting based on this frost date — see the calendar above for exact timing.
What planting zone is Loudoun County, VA?
Loudoun County, Virginia is in USDA Hardiness Zone 7a. The average last spring frost is April 18 and first fall frost is October 19.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Loudoun County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.
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