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When to plant Horehound in Plumas County County,

Plumas County County sits in cold Zone 7b. Plant Horehound May 27–June 10 for the single annual harvest; the October 8 first frost closes the window.

When to Plant Horehound in Plumas County, CA

Plumas County, California Zone 7b June

This month in Plumas County, California

Each item below is timed to Plumas County, California's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 20
Avg. first frost October 8
Soil temp (4") 72°F
Watering Critical
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.

Plumas County, California is in USDA Zone 7b. The average last spring frost is May 20 and the first fall frost is October 8, giving you a growing season of approximately 141 days.

At an elevation of 1,185 feet, Plumas County receives approximately 30.9 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Horehound to ensure they mature before fall.

Plumas County, CA (Zone 7b) Short season
141 days
Last Spring Frost May 20
141 growing days
First Fall Frost October 8

Plumas County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.6

Drainage

Well Drained

Horehound Planting Risk Windows

Early Start (70% safe) ✓ Fits season (1 days to spare)
Transplant: May 18 🍅 Harvest: Aug 3 – Sep 28
Recommended (50%) ✓ Fits season (1 days to spare)
Transplant: May 27 🍅 Harvest: Aug 12 – Oct 7
Safe Start (90%) ✓ Fits season (6 days to spare)
Transplant: Jun 15 🍅 Harvest: Aug 31 – Oct 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 Plumas County

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

Soil pH

Your soil pH (6.6–7.6) is within Horehound's preferred range (6.0–8.0).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). 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 141-day season

Sow every 8.6 weeks. Last sowing by Jul 10 to harvest before frost.

Horehound Water Budget

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

Water stress score is 8/10 — 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 6.9" 0" ❄️ Dormant
Feb 6.2" 0" ❄️ Dormant
Mar 5" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 2.2" 1" 1.2" 🚿 Regular watering
Jun 2.2" 0.2" 2" 🚿 Regular watering
Jul 2.2" 0" 2.2" 🚿 Regular watering
Aug 2.2" 0" 2.2" 🚿 Regular watering
Sep 2.2" 0.3" 1.9" 🚿 Regular watering
Oct 2.2" 1.2" 1" 💧 Light watering
Nov 3" 0" ❄️ Dormant
Dec 4.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Plumas 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 ~949 GDD — county provides 1,621 GDD Excellent fit

Horehound Planting Timeline — Plumas County, CA

Horehound Planting Calendar

Activity When Date Range
Transplant Outdoors May 27 May 27 – Jun 10
Harvest August 12 Aug 12 – Oct 7

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Transplant Outdoors
July
August Harvest
September Harvest
October Harvest
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: ideal

🗺️ USDA Zone

Zone 7b

📆 Growing Season

141 days in Plumas County

Growing Tips for Horehound in Plumas County

Direct sow Horehound outdoors after May 20 in Plumas 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 Plumas County, CA?

Plumas County is in Zone 7b with an average last frost of May 20. Plan your Horehound planting based on this frost date — see the calendar above for exact timing.

What planting zone is Plumas County, CA?

Plumas County, California is in USDA Hardiness Zone 7b. The average last spring frost is May 20 and first fall frost is October 8.

When should I plant Horehound in Plumas County County, ?

In Plumas County County, , plant Horehound after the last frost (around May 20) and before the first frost (around October 8). Best results when soil holds above 50°F.

What growing zone is Plumas County County, for Horehound?

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

Can Horehound grow in Plumas County County's climate?

Yes — Horehound grows well in Plumas County County's temperate climate. Plumas County County averages a 141-day frost-free season, with last frost around May 20 and first frost around October 8.

🌱

Your Plumas County Garden Planner — Free

A 22-page printable planner built for Plumas County (Zone 7b). 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 Plumas County, CA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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