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When to plant Horehound in Washington County, IL

Plant Horehound in Washington County during the brief April 16–April 30 window. With 194 frost-free days, fall plantings can't mature before October 20.

When to Plant Horehound in Washington County, IL

Washington County, Illinois Zone 6b August

What to do in August

We've pulled the most time-sensitive tasks for Washington County, Illinois this August and put them front and centre. Tackle them in order.

Avg. last frost April 9
Avg. first frost October 20
Soil temp (4") 83°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Basket week: horehound

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

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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.

Washington County, Illinois is in USDA Zone 6b. The average last spring frost is April 9 and the first fall frost is October 20, giving you a growing season of approximately 194 days.

At an elevation of 1,126 feet, Washington County receives approximately 33.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Horehound during the growing season.

Washington County, IL (Zone 6b) Moderate season
194 days
Last Spring Frost April 9
194 growing days
First Fall Frost October 20

Washington County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.2

Drainage

Well Drained

Horehound Planting Risk Windows

Early Start (70% safe) ✓ Fits season (51 days to spare)
Transplant: Apr 11 🍅 Harvest: Jun 27 – Aug 22
Recommended (50%) ✓ Fits season (54 days to spare)
Transplant: Apr 16 🍅 Harvest: Jul 2 – Aug 27
Safe Start (90%) ✓ Fits season (54 days to spare)
Transplant: Apr 26 🍅 Harvest: Jul 12 – Sep 6

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 Washington County

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

Soil pH

Your soil pH (5.9–7.2) overlaps with Horehound's range (6.0–8.0), though not a perfect match.

Soil Texture

The silt loam soil in Washington County is excellent for Horehound — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.9%). 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 194-day season

Sow every 8.6 weeks. Last sowing by Jul 22 to harvest before frost.

Horehound Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/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 1.3" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 2.2" 3.7" 0" ✅ Rainfall sufficient
May 2.2" 3.4" 0" ✅ Rainfall sufficient
Jun 2.2" 4.3" 0" ✅ Rainfall sufficient
Jul 2.2" 3.9" 0" ✅ Rainfall sufficient
Aug 2.2" 3.8" 0" ✅ Rainfall sufficient
Sep 2.2" 2.8" 0" ✅ Rainfall sufficient
Oct 2.2" 2.5" 0" ✅ Rainfall sufficient
Nov 2.2" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Washington 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 ~1,258 GDD — county provides 2,958 GDD Excellent fit

Horehound Planting Timeline — Washington County, IL

Horehound Planting Calendar

Activity When Date Range
Transplant Outdoors April 16 Apr 16 – Apr 30
Harvest July 2 Jul 2 – Aug 27

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 6b

📆 Growing Season

194 days in Washington County

Growing Tips for Horehound in Washington County

Direct sow Horehound outdoors after April 09 in Washington 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 Washington County, IL?

Washington County is in Zone 6b with an average last frost of April 9. Plan your Horehound planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, IL?

Washington County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 9 and first fall frost is October 20.

When should I plant Horehound in Washington County, IL?

In Washington County, IL, plant Horehound after the last frost (around April 9) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Washington County, IL for Horehound?

Washington County sits in USDA Zone 6b. Horehound grows reliably in zones 3a through 10b, so it's a good fit here.

Can Horehound grow in Washington County's climate?

Yes — Horehound grows well in Washington County's temperate climate. Washington County averages a 194-day frost-free season, with last frost around April 9 and first frost around October 20.

🌱

Your Washington County Garden Planner — Free

A 22-page printable planner built for Washington County (Zone 6b). 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 Washington County, IL. Local conditions may vary. Last updated: August 2026.

Sources & credits

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