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When to plant Horseradish in Mapleton, IL

In Mapleton, Horseradish is a single-season spring crop — there's no second fall window. Plant May 7–May 21 for an 120–180-day harvest, finishing well before the October 12 first frost.

When to Plant Horseradish in Mapleton, IL

Peoria County, Illinois Zone 6a July

What to do in July

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

Avg. last frost April 23
Avg. first frost October 12
Soil temp (4") 76°F
Watering Moderate
Pest pressure High
Daylight 14.7 hrs

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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.

Mapleton, Illinois is in USDA Zone 6a. The average last spring frost is April 23 and the first fall frost is October 12, giving you a growing season of approximately 172 days.

At an elevation of 884 feet, Peoria County receives approximately 33 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Horseradish during the growing season.

Mapleton, IL (Zone 6a) Moderate season
172 days
Last Spring Frost April 23
172 growing days
First Fall Frost October 12

Mapleton Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7

Drainage

Well Drained

Horseradish Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 1 🍅 Harvest: Sep 4 – Nov 13
Recommended (50%) ✗ May not fit
Transplant: May 7 🍅 Harvest: Sep 10 – Nov 19
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 Mapleton

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

Soil pH

Your soil pH (6.1–7.0) is within Horseradish's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) — Horseradish will thrive.

How to Plant Horseradish

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

Horseradish Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 297 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 1.4" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 3.5" 0.8" 💧 Light watering
May 4.3" 4.2" 0.1" 💧 Light watering
Jun 4.3" 3.9" 0.4" 💧 Light watering
Jul 4.3" 3.2" 1.1" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 1.9" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Peoria 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 ~2,175 GDD — county provides 2,494 GDD Good fit

Horseradish Planting Timeline — Mapleton, IL

Horseradish Planting Calendar

Activity When Date Range
Transplant Outdoors May 7 May 7 – May 21
Harvest September 10 Sep 10 – Nov 19

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

120–180 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

172 days in Peoria County

Growing Tips for Horseradish in Mapleton

Direct sow Horseradish outdoors after April 23 in Peoria County when soil has warmed and frost danger has passed.

Your 172.0-day growing season in Peoria 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 →

When should I plant Horseradish in Mapleton, IL?

In Mapleton, IL, plant Horseradish after the last frost (around April 23) and before the first frost (around October 12). Best results when soil holds above 50°F.

What growing zone is Mapleton, IL for Horseradish?

Mapleton sits in USDA Zone 6a. Horseradish grows reliably in zones 3a through 9b, so it's a good fit here.

Can Horseradish grow in Mapleton's climate?

Yes — Horseradish grows well in Mapleton's temperate climate. Mapleton averages a 172-day frost-free season, with last frost around April 23 and first frost around October 12.

🌱

Your Peoria County Garden Planner — Free

A 22-page printable planner built for Peoria County (Zone 6a). 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 Peoria County, IL. Local conditions may vary. Last updated: July 2026.