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When to Plant Horehound in Cowlitz County, WA

Cowlitz County, Washington Zone 8b May

Your May planting checklist for Cowlitz County, Washington

Here's what deserves your attention in Cowlitz County, Washington this month. Everything below is tailored to Zone 8b and timed around your local frost dates.

Avg. last frost April 15
Avg. first frost October 29
Soil temp (4") 72°F
Watering Moderate
Pest pressure High
Daylight 14.8 hrs

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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.

Cowlitz County, Washington is in USDA Zone 8b. The average last spring frost is April 15 and the first fall frost is October 29, giving you a growing season of approximately 197 days.

At an elevation of 268 feet, Cowlitz County receives approximately 47.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Horehound during the growing season.

Cowlitz County, WA (Zone 8b) Moderate season
197 days
Last Spring Frost April 15
197 growing days
First Fall Frost October 29
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Cowlitz County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (54 days to spare)
Transplant: Apr 16 🍅 Harvest: Jul 2 – Aug 27
Recommended (50%) ✓ Fits season (57 days to spare)
Transplant: Apr 22 🍅 Harvest: Jul 8 – Sep 2
Safe Start (90%) ✓ Fits season (61 days to spare)
Transplant: May 14 🍅 Harvest: Jul 30 – Sep 24

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 Cowlitz County

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

Soil pH

Your soil pH (5.7–6.5) overlaps with Horehound's range (6.0–8.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Horehound will thrive.

How to Plant Horehound

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

Succession Planting Horehound

3
successive plantings in your 197-day season

Sow every 8.6 weeks. Last sowing by Jul 31 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/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 7.2" 0" ❄️ Dormant
Feb 4.6" 0" ❄️ Dormant
Mar 5.1" 0" ❄️ Dormant
Apr 2.2" 3.6" 0" ✅ Rainfall sufficient
May 2.2" 2.9" 0" ✅ Rainfall sufficient
Jun 2.2" 2" 0.2" 💧 Light watering
Jul 2.2" 0.8" 1.4" 🚿 Regular watering
Aug 2.2" 0.9" 1.3" 🚿 Regular watering
Sep 2.2" 1.6" 0.6" 💧 Light watering
Oct 2.2" 3.4" 0" ✅ Rainfall sufficient
Nov 7.6" 0" ❄️ Dormant
Dec 7.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Cowlitz 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 3,004 GDD Excellent fit

Horehound Planting Timeline — Cowlitz County, WA

Horehound Planting Calendar

Activity When Date Range
Transplant Outdoors April 22 Apr 22 – May 6
Harvest July 8 Jul 8 – Sep 2

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
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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 8b

📆 Growing Season

197 days in Cowlitz County

Growing Tips for Horehound in Cowlitz County

Direct sow Horehound outdoors after April 15 in Cowlitz 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 Cowlitz County, WA?

Cowlitz County is in Zone 8b with an average last frost of April 15. Plan your Horehound planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cowlitz County, WA?

Cowlitz County, Washington is in USDA Hardiness Zone 8b. The average last spring frost is April 15 and first fall frost is October 29.

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Your Cowlitz County Garden Planner — Free

A 24-page printable planner built for Cowlitz County (Zone 8b). 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 Cowlitz County, WA. Local conditions may vary. Last updated: May 2026.

Sources & credits

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