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When to Plant Horseradish in Campbell County, KY

Campbell County, Kentucky Zone 6b May

May in Campbell County, Kentucky — your action list

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 18
Avg. first frost October 24
Soil temp (4") 53°F
Watering Moderate
Pest pressure Low
Daylight 14.1 hrs
  1. Get horseradish in the ground

    Your last frost (April 18) has passed. These warm-season crops can handle outdoor soil now.

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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.

Campbell County, Kentucky is in USDA Zone 6b. The average last spring frost is April 18 and the first fall frost is October 24, giving you a growing season of approximately 189 days.

At an elevation of 3,725 feet, Campbell County receives approximately 47.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Horseradish during the growing season.

Campbell County, KY (Zone 6b) Moderate season
189 days
Last Spring Frost April 18
189 growing days
First Fall Frost October 24
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Campbell County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 24 🍅 Harvest: Aug 28 – Nov 6
Recommended (50%) ✗ May not fit
Transplant: May 2 🍅 Harvest: Sep 5 – Nov 14
Safe Start (90%) ✗ May not fit
Transplant: May 22 🍅 Harvest: Sep 25 – Dec 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 Campbell County

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

Soil pH

Your soil pH (5.6–7.0) overlaps with Horseradish's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Campbell County is excellent for Horseradish — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.1%). Annual compost additions will help Horseradish.

How to Plant Horseradish

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 4.2" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 4" 0" ❄️ Dormant
Apr 4.3" 3.5" 0.8" 💧 Light watering
May 4.3" 3.5" 0.8" 💧 Light watering
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 5" 0" ✅ Rainfall sufficient
Aug 4.3" 5.1" 0" ✅ Rainfall sufficient
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 3.3" 0" ❄️ Dormant
Dec 4.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Campbell 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 ~2,738 GDD — county provides 3,449 GDD Good fit

Horseradish Planting Timeline — Campbell County, KY

Horseradish Planting Calendar

Activity When Date Range
Transplant Outdoors May 2 May 2 – May 16
Harvest September 5 Sep 5 – Nov 14

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

120–180 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

189 days in Campbell County

Growing Tips for Horseradish in Campbell County

Direct sow Horseradish outdoors after April 18 in Campbell County when soil has warmed and frost danger has passed.

Your 189.0-day growing season in Campbell County is tight for Horseradish (120.0-180.0 days to maturity). Start indoors and choose early-maturing varieties.

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 Campbell County, KY?

Campbell County is in Zone 6b with an average last frost of April 18. Plan your Horseradish planting based on this frost date — see the calendar above for exact timing.

What planting zone is Campbell County, KY?

Campbell County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 18 and first fall frost is October 24.

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Your Campbell County Garden Planner — Free

A 24-page printable planner built for Campbell County (Zone 6b). 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 Campbell County, KY. 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.