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When to Plant Horseradish in Montrose County, CO

Montrose County, Colorado Zone 6b May

May in Montrose County, Colorado — your action list

May is a pivotal month for Montrose County, Colorado gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost June 13
Avg. first frost September 12
Soil temp (4") 45°F
Watering High
Pest pressure Low
Daylight 14.1 hrs
Looking ahead to June
  • Transplants going out: horseradish

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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.

Montrose County, Colorado is in USDA Zone 6b. The average last spring frost is June 13 and the first fall frost is September 12, giving you a growing season of approximately 91 days.

At an elevation of 6,494 feet, Montrose County receives approximately 18.4 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Horseradish during the growing season. With low rainfall, drip irrigation is essential for growing Horseradish successfully. Mulch heavily to conserve soil moisture.

Montrose County, CO (Zone 6b) Very short season
91 days
Last Spring Frost June 13
91 growing days
First Fall Frost September 12
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Montrose County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 28 🍅 Harvest: Oct 1 – Dec 10
Recommended (50%) ✓ Fits season (246 days to spare)
Transplant: Jun 27 🍅 Harvest: Oct 31 – Jan 9
Safe Start (90%) ✓ Fits season (264 days to spare)
Transplant: Jul 10 🍅 Harvest: Nov 13 – Jan 22

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 Montrose County

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

Soil pH

Your soil pH (6.7–7.9) overlaps with Horseradish's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). 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
0.9″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 147 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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" 0" ❄️ Dormant
Mar 1.4" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 2.3" 0" ❄️ Dormant
Jun 4.3" 1.2" 3.1" 🚿 Regular watering
Jul 4.3" 1.8" 2.5" 🚿 Regular watering
Aug 4.3" 1.7" 2.6" 🚿 Regular watering
Sep 4.3" 1.5" 2.8" 🚿 Regular watering
Oct 1.6" 0" ❄️ Dormant
Nov 1.3" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Montrose 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 ~2,288 GDD — county provides 1,387 GDD May not mature

Horseradish Planting Timeline — Montrose County, CO

Horseradish Planting Calendar

Activity When Date Range
Transplant Outdoors June 27 Jun 27 – Jul 11
Harvest October 31 Oct 31 – Jan 9

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

Month-by-Month Timeline

MonthActivities
January Harvest
February
March
April
May
June Transplant Outdoors
July Transplant Outdoors
August
September
October Harvest
November Harvest
December Harvest
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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 6b

📆 Growing Season

91 days in Montrose County

Growing Tips for Horseradish in Montrose County

Direct sow Horseradish outdoors after June 13 in Montrose County when soil has warmed and frost danger has passed.

Your 91.0-day growing season in Montrose 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.

Montrose County receives only 18" of rain annually. Horseradish needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Montrose County, CO?

Montrose County is in Zone 6b with an average last frost of June 13. Plan your Horseradish planting based on this frost date — see the calendar above for exact timing.

What planting zone is Montrose County, CO?

Montrose County, Colorado is in USDA Hardiness Zone 6b. The average last spring frost is June 13 and first fall frost is September 12.

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Your Montrose County Garden Planner — Free

A 24-page printable planner built for Montrose 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 Montrose County, CO. 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.