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When to Plant Horseradish in McMullen County, TX

McMullen County, Texas Zone 9b May

Your May game plan for McMullen County, Texas

Welcome to May in Zone 9b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost February 20
Avg. first frost December 1
Soil temp (4") 70°F
Watering Low
Pest pressure High
Daylight 13.4 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.

McMullen County, Texas is in USDA Zone 9b. The average last spring frost is February 20 and the first fall frost is December 1, giving you a growing season of approximately 284 days.

At an elevation of 3,741 feet, McMullen County receives approximately 58 inches of rainfall annually with predominantly loam soil. Summer highs average 103°F, so Horseradish may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Horseradish root diseases.

McMullen County, TX (Zone 9b) Year-round
284 days
Last Spring Frost February 20
284 growing days
First Fall Frost December 1

McMullen County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (84 days to spare)
Transplant: Feb 17 🍅 Harvest: Jun 23 – Sep 1
Recommended (50%) ✓ Fits season (74 days to spare)
Transplant: Mar 6 🍅 Harvest: Jul 10 – Sep 18
Safe Start (90%) ✓ Fits season (67 days to spare)
Transplant: Mar 31 🍅 Harvest: Aug 4 – Oct 13

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 McMullen County

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

Soil pH

Your soil pH (6.8–7.2) is within Horseradish's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). 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 442 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 1.6" 0" ❄️ Dormant
Feb 4.3" 2" 2.3" 🚿 Regular watering
Mar 4.3" 3.7" 0.6" 💧 Light watering
Apr 4.3" 6.4" 0" ✅ Rainfall sufficient
May 4.3" 9.4" 0" ✅ Rainfall sufficient
Jun 4.3" 9.8" 0" ✅ Rainfall sufficient
Jul 4.3" 7.3" 0" ✅ Rainfall sufficient
Aug 4.3" 6.5" 0" ✅ Rainfall sufficient
Sep 4.3" 4.6" 0" ✅ Rainfall sufficient
Oct 4.3" 3.5" 0.8" 💧 Light watering
Nov 4.3" 1.7" 2.6" 🚿 Regular watering
Dec 4.3" 1.3" 3" 🚿 Regular watering

Water needs are for active growing months only (Feb–Dec in McMullen 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 ~4,088 GDD — county provides 7,766 GDD Excellent fit

Horseradish Planting Timeline — McMullen County, TX

Horseradish Planting Calendar

Activity When Date Range
Transplant Outdoors March 6 Mar 6 – Mar 20
Harvest July 10 Jul 10 – Sep 18

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

Month-by-Month Timeline

MonthActivities
January
February
March Transplant Outdoors
April
May
June
July Harvest
August Harvest
September Harvest
October
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 9b

📆 Growing Season

284 days in McMullen County

Growing Tips for Horseradish in McMullen County

Direct sow Horseradish outdoors after February 20 in McMullen County when soil has warmed and frost danger has passed.

With summer highs reaching 103°F in McMullen County, provide afternoon shade for Horseradish and water deeply in the morning.

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 McMullen County, TX?

McMullen County is in Zone 9b with an average last frost of February 20. Plan your Horseradish planting based on this frost date — see the calendar above for exact timing.

What planting zone is McMullen County, TX?

McMullen County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 20 and first fall frost is December 1.

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Your McMullen County Garden Planner — Free

A 24-page printable planner built for McMullen County (Zone 9b). 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 McMullen County, TX. 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.