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When to Plant Horseradish in Klickitat County, WA

Klickitat County, Washington Zone 7b May

Your May planting checklist for Klickitat County, Washington

A quick May briefing for Klickitat County, Washington gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 14
Avg. first frost October 19
Soil temp (4") 63°F
Watering High
Pest pressure Low
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.

Klickitat County, Washington is in USDA Zone 7b. The average last spring frost is April 14 and the first fall frost is October 19, giving you a growing season of approximately 188 days.

At an elevation of 466 feet, Klickitat County receives approximately 42 inches of rainfall annually with predominantly silt loam soil. Summer highs average 77°F, so choose short-season varieties of Horseradish to ensure they mature before fall.

Klickitat County, WA (Zone 7b) Moderate season
188 days
Last Spring Frost April 14
188 growing days
First Fall Frost October 19

Klickitat County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 22 🍅 Harvest: Aug 26 – Nov 4
Recommended (50%) ✗ May not fit
Transplant: Apr 28 🍅 Harvest: Sep 1 – Nov 10
Safe Start (90%) ✗ May not fit
Transplant: May 20 🍅 Harvest: Sep 23 – Dec 2

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 Klickitat County

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

Soil pH

Your soil pH (5.3–6.8) overlaps with Horseradish's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.7%) — Horseradish will thrive.

How to Plant Horseradish

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 103 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 5.4" 0" ❄️ Dormant
Feb 4.3" 0" ❄️ Dormant
Mar 4.4" 0" ❄️ Dormant
Apr 4.3" 3.5" 0.8" 💧 Light watering
May 4.3" 2.6" 1.7" 💧 Light watering
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 0.7" 3.6" 🚿 Regular watering
Aug 4.3" 0.9" 3.4" 🚿 Regular watering
Sep 4.3" 1.6" 2.7" 🚿 Regular watering
Oct 4.3" 3.9" 0.4" 💧 Light watering
Nov 6.7" 0" ❄️ Dormant
Dec 6.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Klickitat 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 ~1,162 GDD — county provides 1,457 GDD Good fit

Horseradish Planting Timeline — Klickitat County, WA

Horseradish Planting Calendar

Activity When Date Range
Transplant Outdoors April 28 Apr 28 – May 12
Harvest September 1 Sep 1 – Nov 10

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
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: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

188 days in Klickitat County

Growing Tips for Horseradish in Klickitat County

Direct sow Horseradish outdoors after April 14 in Klickitat County when soil has warmed and frost danger has passed.

Your 188.0-day growing season in Klickitat 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 Klickitat County, WA?

Klickitat County is in Zone 7b with an average last frost of April 14. Plan your Horseradish planting based on this frost date — see the calendar above for exact timing.

What planting zone is Klickitat County, WA?

Klickitat County, Washington is in USDA Hardiness Zone 7b. The average last spring frost is April 14 and first fall frost is October 19.

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Your Klickitat County Garden Planner — Free

A 24-page printable planner built for Klickitat County (Zone 7b). 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 Klickitat County, WA. 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.