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When to Plant Horehound in Lake County, CA

Lake County, California Zone 9a May

May in Lake County, California — your action list

Your garden in Lake County, California is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost March 2
Avg. first frost November 27
Soil temp (4") 71°F
Watering Critical
Pest pressure High
Daylight 14.1 hrs
  1. Basket week: horehound

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

To set up a strong June, finish these tasks
  • 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.

Lake County, California is in USDA Zone 9a. The average last spring frost is March 2 and the first fall frost is November 27, giving you a growing season of approximately 270 days.

At an elevation of 154 feet, Lake County receives approximately 30.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 83°F, so choose short-season varieties of Horehound to ensure they mature before fall. Sandy soil warms quickly in spring — great for early planting — but Horehound will need more frequent watering and organic matter to retain nutrients.

Lake County, CA (Zone 9a) Year-round
270 days
Last Spring Frost March 2
270 growing days
First Fall Frost November 27

Lake County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.1-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (138 days to spare)
Transplant: Feb 21 🍅 Harvest: May 9 – Jul 4
Recommended (50%) ✓ Fits season (130 days to spare)
Transplant: Mar 9 🍅 Harvest: May 25 – Jul 20
Safe Start (90%) ✓ Fits season (101 days to spare)
Transplant: Apr 24 🍅 Harvest: Jul 10 – Sep 4

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 Lake County

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

Soil pH

Your soil pH (6.1–6.9) is within Horehound's preferred range (6.0–8.0).

Soil Texture

Sandy soil in Lake County warms quickly in spring but drains fast. Horehound will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Horehound.

How to Plant Horehound

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

Succession Planting Horehound

4
successive plantings in your 270-day season

Sow every 8.6 weeks. Last sowing by Aug 29 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 65 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 6.2" 0" ❄️ Dormant
Feb 6.5" 0" ❄️ Dormant
Mar 2.2" 4.6" 0" ✅ Rainfall sufficient
Apr 2.2" 2.7" 0" ✅ Rainfall sufficient
May 2.2" 0.8" 1.4" 🚿 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" 1.1" 1.1" 🚿 Regular watering
Nov 2.2" 3" 0" ✅ Rainfall sufficient
Dec 5.1" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Lake 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 ~1,011 GDD — county provides 3,307 GDD Excellent fit

Horehound Planting Timeline — Lake County, CA

Horehound Planting Calendar

Activity When Date Range
Transplant Outdoors March 9 Mar 9 – Mar 23
Harvest May 25 May 25 – Jul 20

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

75–90 days

🧪 Soil pH

Needs 6–8 · Your soil: ideal

🗺️ USDA Zone

Zone 9a

📆 Growing Season

270 days in Lake County

Growing Tips for Horehound in Lake County

Direct sow Horehound outdoors after March 02 in Lake County when soil has warmed and frost danger has passed.

Sandy soil in Lake County dries quickly — mulch Horehound with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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 Lake County, CA?

Lake County is in Zone 9a with an average last frost of March 2. Plan your Horehound planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lake County, CA?

Lake County, California is in USDA Hardiness Zone 9a. The average last spring frost is March 2 and first fall frost is November 27.

🌱

Your Lake County Garden Planner — Free

A 24-page printable planner built for Lake County (Zone 9a). 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 Lake County, CA. 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.