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When to Plant Horehound in Warren County, KY

Warren County, Kentucky Zone 7a April

Your April gardening checklist

Here's what deserves your attention in Warren County, Kentucky this month. Everything below is tailored to Zone 7a and timed around your local frost dates.

Avg. last frost April 8
Avg. first frost October 28
Soil temp (4") 42°F
Watering Moderate
Pest pressure Low
Daylight 13 hrs
  1. Plant out horehound

    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.

Warren County, Kentucky is in USDA Zone 7a. The average last spring frost is April 8 and the first fall frost is October 28, giving you a growing season of approximately 203 days.

At an elevation of 3,957 feet, Warren County receives approximately 44.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Horehound during the growing season.

Warren County, KY (Zone 7a) Long season
203 days
Last Spring Frost April 8
203 growing days
First Fall Frost October 28

Warren County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (61 days to spare)
Transplant: Apr 10 🍅 Harvest: Jun 26 – Aug 21
Recommended (50%) ✓ Fits season (63 days to spare)
Transplant: Apr 15 🍅 Harvest: Jul 1 – Aug 26
Safe Start (90%) ✓ Fits season (59 days to spare)
Transplant: May 1 🍅 Harvest: Jul 17 – Sep 11

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 Warren County

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

Soil pH

Your soil pH (5.3–7.0) overlaps with Horehound's range (6.0–8.0), though not a perfect match.

Soil Texture

The silt loam soil in Warren 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

3
successive plantings in your 203-day season

Sow every 8.6 weeks. Last sowing by Jul 30 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 3.3" 0" ❄️ Dormant
Feb 3.5" 0" ❄️ Dormant
Mar 4.3" 0" ❄️ Dormant
Apr 2.2" 3.4" 0" ✅ Rainfall sufficient
May 2.2" 3.7" 0" ✅ Rainfall sufficient
Jun 2.2" 4" 0" ✅ Rainfall sufficient
Jul 2.2" 5" 0" ✅ Rainfall sufficient
Aug 2.2" 4.7" 0" ✅ Rainfall sufficient
Sep 2.2" 3.1" 0" ✅ Rainfall sufficient
Oct 2.2" 2.7" 0" ✅ Rainfall sufficient
Nov 3.2" 0" ❄️ Dormant
Dec 3.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Warren 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 ~1,320 GDD — county provides 3,248 GDD Excellent fit

Horehound Planting Timeline — Warren County, KY

Horehound Planting Calendar

Activity When Date Range
Transplant Outdoors April 15 Apr 15 – Apr 29
Harvest July 1 Jul 1 – Aug 26

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
May
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

203 days in Warren County

Growing Tips for Horehound in Warren County

Direct sow Horehound outdoors after April 08 in Warren 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 →

Frequently Asked Questions

When should I plant Horehound in Warren County, KY?

Warren County is in Zone 7a with an average last frost of April 8. Plan your Horehound planting based on this frost date — see the calendar above for exact timing.

What planting zone is Warren County, KY?

Warren County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 8 and first fall frost is October 28.

🌱

Your Warren County Garden Planner — Free

A 24-page printable planner built for Warren 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Warren County, KY. Local conditions may vary. Last updated: April 2026.

Sources & credits

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