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When to Plant Horehound in San Benito County, CA

San Benito County, California Zone 9b May

What to do in May

A quick May briefing for San Benito County, California gardeners — what's urgent, what's next, and what can wait.

Avg. last frost February 21
Avg. first frost November 29
Soil temp (4") 76°F
Watering Critical
Pest pressure High
Daylight 14 hrs
  1. Bring in the horehound

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

Looking ahead to June
  • 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.

San Benito County, California is in USDA Zone 9b. The average last spring frost is February 21 and the first fall frost is November 29, giving you a growing season of approximately 281 days.

At an elevation of 149 feet, San Benito County receives approximately 13 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Horehound during the growing season. With low rainfall, drip irrigation is essential for growing Horehound successfully. Mulch heavily to conserve soil moisture.

San Benito County, CA (Zone 9b) Year-round
281 days
Last Spring Frost February 21
281 growing days
First Fall Frost November 29

San Benito County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (150 days to spare)
Transplant: Feb 12 🍅 Harvest: Apr 30 – Jun 25
Recommended (50%) ✓ Fits season (141 days to spare)
Transplant: Feb 28 🍅 Harvest: May 16 – Jul 11
Safe Start (90%) ✓ Fits season (117 days to spare)
Transplant: Apr 15 🍅 Harvest: Jul 1 – Aug 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 San Benito County

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

Soil pH

Your soil pH (6.5–7.4) is within Horehound's preferred range (6.0–8.0).

Soil Texture

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

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 281-day season

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

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.2″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 923 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 2.5" 0" ❄️ Dormant
Feb 2.2" 2.6" 0" ✅ Rainfall sufficient
Mar 2.2" 2.2" 0" ✅ Rainfall sufficient
Apr 2.2" 1.1" 1.1" 🚿 Regular watering
May 2.2" 0.3" 1.9" 🚿 Regular watering
Jun 2.2" 0.1" 2.1" 🚿 Regular watering
Jul 2.2" 0" 2.2" 🚿 Regular watering
Aug 2.2" 0" 2.2" 🚿 Regular watering
Sep 2.2" 0.1" 2.1" 🚿 Regular watering
Oct 2.2" 0.5" 1.7" 🚿 Regular watering
Nov 2.2" 1.3" 0.9" 💧 Light watering
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in San Benito 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 ~1,691 GDD — county provides 5,781 GDD Excellent fit

Horehound Planting Timeline — San Benito County, CA

Horehound Planting Calendar

Activity When Date Range
Transplant Outdoors February 28 Feb 28 – Mar 14
Harvest May 16 May 16 – Jul 11

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

Month-by-Month Timeline

MonthActivities
January
February Transplant Outdoors
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 · 1-2 times/week

📅 Days to Maturity

75–90 days

🧪 Soil pH

Needs 6–8 · Your soil: ideal

🗺️ USDA Zone

Zone 9b

📆 Growing Season

281 days in San Benito County

Growing Tips for Horehound in San Benito County

Direct sow Horehound outdoors after February 21 in San Benito County when soil has warmed and frost danger has passed.

San Benito County receives only 13" of rain annually. Horehound needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 San Benito County, CA?

San Benito County is in Zone 9b with an average last frost of February 21. Plan your Horehound planting based on this frost date — see the calendar above for exact timing.

What planting zone is San Benito County, CA?

San Benito County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 21 and first fall frost is November 29.

🌱

Your San Benito County Garden Planner — Free

A 24-page printable planner built for San Benito County (Zone 9b). 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 San Benito 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.