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When to Plant Horseradish in Valdez-Cordova, AK

Valdez-Cordova, Alaska Zone 5b May

Top priorities for Valdez-Cordova, Alaska gardeners in May

Each item below is timed to Valdez-Cordova, Alaska's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 12
Avg. first frost October 5
Soil temp (4") 47°F
Watering High
Pest pressure Low
Daylight 17.1 hrs
  1. Set out horseradish seedlings

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

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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.

Valdez-Cordova, Alaska is in USDA Zone 5b. The average last spring frost is May 12 and the first fall frost is October 5, giving you a growing season of approximately 146 days.

At an elevation of 2,888 feet, Valdez-Cordova receives approximately 38.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 66°F, so choose short-season varieties of Horseradish to ensure they mature before fall.

Valdez-Cordova, AK (Zone 5b) Short season
146 days
Last Spring Frost May 12
146 growing days
First Fall Frost October 5
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Valdez-Cordova Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 14 🍅 Harvest: Sep 17 – Oct 29
Recommended (50%) ✗ May not fit
Transplant: May 26 🍅 Harvest: Sep 29 – Nov 10
Safe Start (90%) ✗ May not fit
Transplant: Jun 18 🍅 Harvest: Oct 22 – Dec 3

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 Valdez-Cordova

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

Soil pH

Your soil pH (5.0–6.8) is more acidic than Horseradish prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Horseradish.

Organic Matter

Organic matter is excellent (6.2%) — 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
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 1.9" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 1.2" 0" ❄️ Dormant
May 4.3" 1.5" 2.8" 🚿 Regular watering
Jun 4.3" 2.9" 1.4" 💧 Light watering
Jul 4.3" 5.3" 0" ✅ Rainfall sufficient
Aug 4.3" 5.5" 0" ✅ Rainfall sufficient
Sep 4.3" 6" 0" ✅ Rainfall sufficient
Oct 4.3" 5.3" 0" ✅ Rainfall sufficient
Nov 2.9" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Valdez-Cordova). 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 ~0 GDD — county provides 0 GDD May not mature

Horseradish Planting Timeline — Valdez-Cordova, AK

Horseradish Planting Calendar

Activity When Date Range
Transplant Outdoors May 26 May 26 – Jun 9
Harvest September 29 Sep 29 – Nov 10

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Transplant Outdoors
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: too_acidic

🗺️ USDA Zone

Zone 5b

📆 Growing Season

146 days in Valdez-Cordova

Growing Tips for Horseradish in Valdez-Cordova

Direct sow Horseradish outdoors after May 12 in Valdez-Cordova when soil has warmed and frost danger has passed.

Your 146.0-day growing season in Valdez-Cordova 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 Valdez-Cordova, AK?

Valdez-Cordova is in Zone 5b with an average last frost of May 12. Plan your Horseradish planting based on this frost date — see the calendar above for exact timing.

What planting zone is Valdez-Cordova, AK?

Valdez-Cordova, Alaska is in USDA Hardiness Zone 5b. The average last spring frost is May 12 and first fall frost is October 5.

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Your Valdez-Cordova Garden Planner — Free

A 24-page printable planner built for Valdez-Cordova (Zone 5b). 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 Valdez-Cordova, AK. 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.