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When to Plant Horseradish in Flagler County, FL

Flagler County, Florida Zone 9b May

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Avg. last frost February 5
Avg. first frost December 17
Soil temp (4") 77°F
Watering Moderate
Pest pressure High
Daylight 13.5 hrs
June prep starts now
  • First harvests: horseradish

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Horseradish is a vigorous perennial grown for its pungent, spicy roots used as a condiment. Once established, it can be difficult to eradicate, so choose its location carefully.

Flagler County, Florida is in USDA Zone 9b. The average last spring frost is February 5 and the first fall frost is December 17, giving you a growing season of approximately 315 days.

At an elevation of 134 feet, Flagler County receives approximately 54.2 inches of rainfall annually with predominantly sand soil. Summer highs average 99°F, so Horseradish may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Horseradish will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Horseradish root diseases.

Flagler County, FL (Zone 9b) Year-round
315 days
Last Spring Frost February 5
315 growing days
First Fall Frost December 17
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Flagler County Soil Profile

Soil Type

Sand

Soil pH

5.1-5.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (110 days to spare)
Transplant: Feb 5 🍅 Harvest: Jun 11 – Aug 20
Recommended (50%) ✓ Fits season (105 days to spare)
Transplant: Feb 19 🍅 Harvest: Jun 25 – Sep 3
Safe Start (90%) ✓ Fits season (91 days to spare)
Transplant: Mar 14 🍅 Harvest: Jul 18 – Sep 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 Flagler County

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

Soil pH

Your soil pH (5.1–5.7) is more acidic than Horseradish prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Horseradish.

Organic Matter

Organic matter is low (1.6%). Add 2-3 inches of compost before planting Horseradish.

How to Plant Horseradish

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,630 gal / 100 sq ft

Monthly Watering Guide for Horseradish

Horseradish needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Horseradish Needs Rainfall You Supplement Action
Jan 2.7" 0" ❄️ Dormant
Feb 4.3" 2.5" 1.8" 💧 Light watering
Mar 4.3" 3" 1.3" 💧 Light watering
Apr 4.3" 2.2" 2.1" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 8.8" 0" ✅ Rainfall sufficient
Jul 4.3" 7.7" 0" ✅ Rainfall sufficient
Aug 4.3" 7.4" 0" ✅ Rainfall sufficient
Sep 4.3" 6.9" 0" ✅ Rainfall sufficient
Oct 4.3" 4.7" 0" ✅ Rainfall sufficient
Nov 4.3" 2" 2.3" 🚿 Regular watering
Dec 4.3" 2.5" 1.8" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in Flagler County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Horseradish 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.

Horseradish needs ~3,638 GDD — county provides 7,663 GDD Excellent fit

Horseradish Planting Timeline — Flagler County, FL

Horseradish Planting Calendar

Activity When Date Range
Transplant Outdoors February 19 Feb 19 – Mar 5
Harvest June 25 Jun 25 – Sep 3

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

120–180 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

315 days in Flagler County

Growing Tips for Horseradish in Flagler County

Direct sow Horseradish outdoors after February 05 in Flagler County when soil has warmed and frost danger has passed.

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

With summer highs reaching 99°F in Flagler County, provide afternoon shade for Horseradish and water deeply in the morning.

Common pests for Horseradish in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Plant root cuttings at a 45-degree angle in early spring. Harvest roots in late fall for strongest flavor. Contain the plant with barriers or grow in large containers.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Horseradish in Flagler County, FL?

Flagler County is in Zone 9b with an average last frost of February 5. Plan your Horseradish planting based on this frost date — see the calendar above for exact timing.

What planting zone is Flagler County, FL?

Flagler County, Florida is in USDA Hardiness Zone 9b. The average last spring frost is February 5 and first fall frost is December 17.

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Your Flagler County Garden Planner — Free

A 24-page printable planner built for Flagler 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 Flagler 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.