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When to plant Horehound in Knox County County,

Knox County County sits in cold Zone 7a. Plant Horehound April 26–May 10 for the single annual harvest; the October 21 first frost closes the window.

When to Plant Horehound in Knox County, KY

Knox County, Kentucky Zone 7a June

Your June planting checklist for Knox County, Kentucky

Your garden in Knox County, Kentucky is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost April 19
Avg. first frost October 21
Soil temp (4") 68°F
Watering Low
Pest pressure High
Daylight 14.5 hrs
Get ahead of July
  • First harvests: horehound

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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.

Knox County, Kentucky is in USDA Zone 7a. The average last spring frost is April 19 and the first fall frost is October 21, giving you a growing season of approximately 185 days.

At an elevation of 2,802 feet, Knox County receives approximately 46.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Horehound during the growing season.

Knox County, KY (Zone 7a) Moderate season
185 days
Last Spring Frost April 19
185 growing days
First Fall Frost October 21

Knox County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7

Drainage

Well Drained

Horehound Planting Risk Windows

Early Start (70% safe) ✓ Fits season (48 days to spare)
Transplant: Apr 19 🍅 Harvest: Jul 5 – Aug 30
Recommended (50%) ✓ Fits season (45 days to spare)
Transplant: Apr 26 🍅 Harvest: Jul 12 – Sep 6
Safe Start (90%) ✓ Fits season (37 days to spare)
Transplant: May 16 🍅 Harvest: Aug 1 – Sep 26

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 Knox 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 Knox 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 (3.0%). Annual compost additions will help Horehound.

How to Plant Horehound

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Horehound

2
successive plantings in your 185-day season

Sow every 8.6 weeks. Last sowing by Jul 23 to harvest before frost.

Horehound Water Budget

Plant needs
0.5″/week
Rainfall provides
1.1″/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 4" 0" ❄️ Dormant
Mar 4.3" 0" ❄️ Dormant
Apr 2.2" 3.8" 0" ✅ Rainfall sufficient
May 2.2" 3.2" 0" ✅ Rainfall sufficient
Jun 2.2" 3.9" 0" ✅ Rainfall sufficient
Jul 2.2" 4.8" 0" ✅ Rainfall sufficient
Aug 2.2" 4.9" 0" ✅ Rainfall sufficient
Sep 2.2" 3.2" 0" ✅ Rainfall sufficient
Oct 2.2" 3.1" 0" ✅ Rainfall sufficient
Nov 3.8" 0" ❄️ Dormant
Dec 4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Knox 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 ~1,196 GDD — county provides 2,682 GDD Excellent fit

Horehound Planting Timeline — Knox County, KY

Horehound Planting Calendar

Activity When Date Range
Transplant Outdoors April 26 Apr 26 – May 10
Harvest July 12 Jul 12 – Sep 6

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

Month-by-Month Timeline

MonthActivities
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: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

185 days in Knox County

Growing Tips for Horehound in Knox County

Direct sow Horehound outdoors after April 19 in Knox 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 Knox County, KY?

Knox County is in Zone 7a with an average last frost of April 19. Plan your Horehound planting based on this frost date — see the calendar above for exact timing.

What planting zone is Knox County, KY?

Knox County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 19 and first fall frost is October 21.

When should I plant Horehound in Knox County County, ?

In Knox County County, , plant Horehound after the last frost (around April 19) and before the first frost (around October 21). Best results when soil holds above 50°F.

What growing zone is Knox County County, for Horehound?

Knox County County sits in USDA Zone 7a. Horehound grows reliably in zones 3a through 10b, so it's a good fit here.

Can Horehound grow in Knox County County's climate?

Yes — Horehound grows well in Knox County County's temperate climate. Knox County County averages a 185-day frost-free season, with last frost around April 19 and first frost around October 21.

🌱

Your Knox County Garden Planner — Free

A 22-page printable planner built for Knox 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.

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

Sources & credits

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