When to Plant Horseradish in Ashland County, WI
May in Ashland County, Wisconsin — your action list
Your Ashland County, Wisconsin garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
A few tasks this May that'll pay off in June
- Transplants going out: horseradish
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.
Ashland County, Wisconsin is in USDA Zone 4a. The average last spring frost is May 20 and the first fall frost is September 27, giving you a growing season of approximately 130 days.
At an elevation of 705 feet, Ashland County receives approximately 30.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 79°F, so choose short-season varieties of Horseradish to ensure they mature before fall.
Ashland County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7
Drainage
Well Drained
Plant Planting Risk Windows
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 Ashland County
How your county's soil matches Horseradish's growing requirements.
Soil pH
Your soil pH (6.0–7.0) is within Horseradish's preferred range (6.0–7.5).
Soil Texture
The silt loam soil in Ashland County is excellent for Horseradish — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.9%) — Horseradish will thrive.
How to Plant Horseradish
Plant Water Budget
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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | — | 2.7" | 0" | ❄️ Dormant |
| May | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Jun | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Jul | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Aug | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Sep | 4.3" | 2.3" | 2" | 💧 Light watering |
| Oct | — | 2.7" | 0" | ❄️ Dormant |
| Nov | — | 2.3" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Ashland 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 Planting Timeline — Ashland County, WI
Horseradish Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | June 3 | Jun 3 – Jun 17 |
| Harvest | October 7 | Oct 7 – Oct 28 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Transplant Outdoors |
| July | — |
| August | — |
| September | — |
| October | Harvest |
| November | — |
| 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 4a
📆 Growing Season
130 days in Ashland County
Growing Tips for Horseradish in Ashland County
Direct sow Horseradish outdoors after May 20 in Ashland County when soil has warmed and frost danger has passed.
Your 130.0-day growing season in Ashland 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 →
Horseradish in Other Locations
Frequently Asked Questions
When should I plant Horseradish in Ashland County, WI?
Ashland County is in Zone 4a with an average last frost of May 20. Plan your Horseradish planting based on this frost date — see the calendar above for exact timing.
What planting zone is Ashland County, WI?
Ashland County, Wisconsin is in USDA Hardiness Zone 4a. The average last spring frost is May 20 and first fall frost is September 27.
Your Ashland County Garden Planner — Free
A 24-page printable planner built for Ashland County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.