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When to Plant Horehound in Lassen County, CA

Horehound is a woolly, drought-tolerant perennial herb traditionally used for cough remedies and candy. It has a distinctive bitter, menthol-like flavor.

Lassen County, California is in USDA Zone 6b. The average last spring frost is May 28 and the first fall frost is September 29, giving you a growing season of approximately 124 days.

At an elevation of 1,854 feet, Lassen County receives approximately 43.7 inches of rainfall annually with predominantly loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Horehound to ensure they mature before fall.

Lassen County, CA (Zone 6b) Short season
124 days
Last Spring Frost May 28
124 growing days
First Fall Frost September 29

Lassen County Soil Profile

Soil Type

Loam

Soil pH

6.1-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 25 🍅 Harvest: Aug 10 – Oct 5
Recommended (50%) ✗ May not fit
Transplant: Jun 4 🍅 Harvest: Aug 20 – Oct 15
Safe Start (90%) ✗ May not fit
Transplant: Jun 26 🍅 Harvest: Sep 11 – Nov 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 Lassen County

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

Soil pH

Your soil pH (6.1โ€“7.5) is within Horehound's preferred range (6.0โ€“8.0).

Soil Texture

The loam soil in Lassen County is excellent for Horehound โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Horehound.

How to Plant Horehound

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

Plant Water Budget

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

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

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 โ€” 9.2" 0" โ„๏ธ Dormant
Feb โ€” 9.8" 0" โ„๏ธ Dormant
Mar โ€” 7.7" 0" โ„๏ธ Dormant
Apr โ€” 3.2" 0" โ„๏ธ Dormant
May 2.2" 1" 1.2" ๐Ÿšฟ Regular watering
Jun 2.2" 0.2" 2" ๐Ÿšฟ Regular watering
Jul 2.2" 0" 2.2" ๐Ÿšฟ Regular watering
Aug 2.2" 0" 2.2" ๐Ÿšฟ Regular watering
Sep 2.2" 0.5" 1.7" ๐Ÿšฟ Regular watering
Oct โ€” 1.7" 0" โ„๏ธ Dormant
Nov โ€” 3.9" 0" โ„๏ธ Dormant
Dec โ€” 6.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Lassen County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,072 GDD — county provides 1,612 GDD Excellent fit

Horehound Planting Timeline โ€” Lassen County, CA

Horehound Planting Calendar

Activity When Date Range
Transplant Outdoors June 4 Jun 4 โ€“ Jun 18
Harvest August 20 Aug 20 โ€“ Oct 15

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May โ€”
June Transplant Outdoors
July โ€”
August Harvest
September Harvest
October Harvest
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

75โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“8 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

124 days in Lassen County

Growing Tips for Horehound in Lassen County

Direct sow Horehound outdoors after May 28 in Lassen 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 Lassen County, CA?

Lassen County is in Zone 6b with an average last frost of May 28. Plan your Horehound planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Lassen County, CA?

Lassen County, California is in USDA Hardiness Zone 6b. The average last spring frost is May 28 and first fall frost is September 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Lassen County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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