When to Plant Horehound in Ventura County, CA
Your May gardening checklist
Welcome to May in Zone 10a. These are the moves that will have the biggest impact on your growing season.
June prep starts now
- First harvests: horehound
Horehound is a woolly, drought-tolerant perennial herb traditionally used for cough remedies and candy. It has a distinctive bitter, menthol-like flavor.
Ventura County, California is in USDA Zone 10a. The average last spring frost is March 18 and the first fall frost is November 15, giving you a growing season of approximately 242 days.
At an elevation of 2,094 feet, Ventura County receives approximately 19.4 inches of rainfall annually with predominantly loam soil. Summer highs average 88°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.
Ventura County Soil Profile
Soil Type
Loam
Soil pH
6-7.7
Drainage
Well Drained
Plant Planting Risk Windows
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 Ventura County
How your county's soil matches Horehound's growing requirements.
Soil pH
Your soil pH (6.0–7.7) is within Horehound's preferred range (6.0–8.0).
Soil Texture
The loam soil in Ventura County is excellent for Horehound — 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
Succession Planting Horehound
Sow every 8.6 weeks. Last sowing by Aug 17 to harvest before frost.
Plant Water Budget
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 | — | 3.8" | 0" | ❄️ Dormant |
| Feb | — | 4.4" | 0" | ❄️ Dormant |
| Mar | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| May | 2.2" | 0.6" | 1.6" | 🚿 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" | 0.2" | 2" | 🚿 Regular watering |
| Oct | 2.2" | 0.8" | 1.4" | 🚿 Regular watering |
| Nov | 2.2" | 1.7" | 0.5" | 💧 Light watering |
| Dec | — | 3.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Ventura 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 Planting Timeline — Ventura County, CA
Horehound Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | March 25 | Mar 25 – Apr 8 |
| Harvest | June 10 | Jun 10 – Aug 5 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Transplant Outdoors |
| April | Transplant Outdoors |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| 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 10a
📆 Growing Season
242 days in Ventura County
Growing Tips for Horehound in Ventura County
Direct sow Horehound outdoors after March 18 in Ventura County when soil has warmed and frost danger has passed.
Ventura County receives only 19" 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 →
Horehound in Other Locations
Frequently Asked Questions
When should I plant Horehound in Ventura County, CA?
Ventura County is in Zone 10a with an average last frost of March 18. Plan your Horehound planting based on this frost date — see the calendar above for exact timing.
What planting zone is Ventura County, CA?
Ventura County, California is in USDA Hardiness Zone 10a. The average last spring frost is March 18 and first fall frost is November 15.
Your Ventura County Garden Planner — Free
A 24-page printable planner built for Ventura County (Zone 10a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.