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When to Plant Horehound in Indian River County, FL

Indian River County, Florida Zone 10a May

May in Indian River County, Florida — your action list

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

Avg. last frost January 26
Avg. first frost December 20
Soil temp (4") 78°F
Watering Moderate
Pest pressure High
Daylight 13.4 hrs
  1. Bring in the horehound

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Coming up in June — start thinking about
  • 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.

Indian River County, Florida is in USDA Zone 10a. The average last spring frost is January 26 and the first fall frost is December 20, giving you a growing season of approximately 328 days.

At an elevation of 317 feet, Indian River County receives approximately 52.7 inches of rainfall annually with predominantly sand soil. Summer highs average 97°F, so Horehound may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Horehound will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Horehound root diseases.

Indian River County, FL (Zone 10a) Year-round
328 days
Last Spring Frost January 26
328 growing days
First Fall Frost December 20

Indian River County Soil Profile

Soil Type

Sand

Soil pH

5.2-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (186 days to spare)
Transplant: Jan 26 🍅 Harvest: Apr 13 – Jun 8
Recommended (50%) ✓ Fits season (188 days to spare)
Transplant: Feb 2 🍅 Harvest: Apr 20 – Jun 15
Safe Start (90%) ✓ Fits season (169 days to spare)
Transplant: Feb 25 🍅 Harvest: May 13 – Jul 8

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 Indian River County

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

Soil pH

Your soil pH (5.2–6.2) is more acidic than Horehound prefers (6.0–8.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Indian River 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 low (1.5%). Add 2-3 inches of compost before planting Horehound.

How to Plant Horehound

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

Succession Planting Horehound

5
successive plantings in your 328-day season

Sow every 8.6 weeks. Last sowing by Sep 21 to harvest before frost.

Plant Water Budget

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

Water stress score is 6/10 — 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 2.2" 2.5" 0" ✅ Rainfall sufficient
Feb 2.2" 2.5" 0" ✅ Rainfall sufficient
Mar 2.2" 2.8" 0" ✅ Rainfall sufficient
Apr 2.2" 2.5" 0" ✅ Rainfall sufficient
May 2.2" 3.3" 0" ✅ Rainfall sufficient
Jun 2.2" 7.8" 0" ✅ Rainfall sufficient
Jul 2.2" 7.2" 0" ✅ Rainfall sufficient
Aug 2.2" 8.2" 0" ✅ Rainfall sufficient
Sep 2.2" 7.2" 0" ✅ Rainfall sufficient
Oct 2.2" 4.4" 0" ✅ Rainfall sufficient
Nov 2.2" 2.3" 0" ✅ Rainfall sufficient
Dec 2.2" 1.9" 0.3" 💧 Light watering

Water needs are for active growing months only (Jan–Dec in Indian River 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 ~1,877 GDD — county provides 7,484 GDD Excellent fit

Horehound Planting Timeline — Indian River County, FL

Horehound Planting Calendar

Activity When Date Range
Transplant Outdoors February 2 Feb 2 – Feb 16
Harvest April 20 Apr 20 – Jun 15

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 10a

📆 Growing Season

328 days in Indian River County

Growing Tips for Horehound in Indian River County

Direct sow Horehound outdoors after January 26 in Indian River County when soil has warmed and frost danger has passed.

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

With summer highs reaching 97°F in Indian River County, provide afternoon shade for Horehound and water deeply in the morning.

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 Indian River County, FL?

Indian River County is in Zone 10a with an average last frost of January 26. Plan your Horehound planting based on this frost date — see the calendar above for exact timing.

What planting zone is Indian River County, FL?

Indian River County, Florida is in USDA Hardiness Zone 10a. The average last spring frost is January 26 and first fall frost is December 20.

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Your Indian River County Garden Planner — Free

A 24-page printable planner built for Indian River 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.

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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 Indian River County, FL. 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.