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When to Plant Radish in Denton County, TX

Radishes are one of the fastest-growing vegetables, with some varieties ready in under a month. They come in round, elongated, and large winter types.

Denton County, Texas is in USDA Zone 8a. The average last spring frost is March 10 and the first fall frost is November 20, giving you a growing season of approximately 255 days.

At an elevation of 1,848 feet, Denton County receives approximately 64.5 inches of rainfall annually with predominantly clay soil. Summer highs average 90ยฐF, providing good warmth for Radish during the growing season. Clay soil retains moisture well for Radish, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Radish root diseases.

Denton County, TX (Zone 8a) Long season
255 days
Last Spring Frost March 10
255 growing days
First Fall Frost November 20

Denton County Soil Profile

Soil Type

Clay

Soil pH

6.7-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (205 days to spare)
Transplant: Mar 2 🍅 Harvest: Mar 30 – Apr 20
Recommended (50%) ✓ Fits season (206 days to spare)
Transplant: Mar 10 🍅 Harvest: Apr 7 – Apr 28
Safe Start (90%) ✓ Fits season (191 days to spare)
Transplant: Apr 11 🍅 Harvest: May 9 – May 30

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 Denton County

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

Soil pH

Your soil pH (6.7โ€“8.1) is more alkaline than Radish prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Your soil has 40% clay, which can cause forked or stunted roots for Radish. Use raised beds with loose, sandy mix for best results.

Drainage

Drainage is adequate for Radish.

Organic Matter

Organic matter is moderate (3.2%). Annual compost additions will help Radish.

How to Plant Radish

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Radish

14
successive plantings in your 255-day season

Sow every 2.4 weeks. Last sowing by Oct 16 to harvest before frost.

For a dedicated fall crop, sow by Sep 11.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Radish

Radish needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Radish Needs Rainfall You Supplement Action
Jan โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 2.1" 0" โ„๏ธ Dormant
Mar 2.2" 4.2" 0" โœ… Rainfall sufficient
Apr 2.2" 7.5" 0" โœ… Rainfall sufficient
May 2.2" 9.6" 0" โœ… Rainfall sufficient
Jun 2.2" 10.2" 0" โœ… Rainfall sufficient
Jul 2.2" 7.6" 0" โœ… Rainfall sufficient
Aug 2.2" 8" 0" โœ… Rainfall sufficient
Sep 2.2" 6.4" 0" โœ… Rainfall sufficient
Oct 2.2" 3.5" 0" โœ… Rainfall sufficient
Nov 2.2" 2.4" 0" โœ… Rainfall sufficient
Dec โ€” 1.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Denton County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Radish 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" โ€” every day above 50ยฐF 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.

Radish needs ~499 GDD — county provides 4,462 GDD Excellent fit

Radish Planting Timeline โ€” Denton County, TX

Radish Planting Calendar

Activity When Date Range
Direct Sow February 24 Feb 24 โ€“ Mar 17
Harvest March 24 Mar 24 โ€“ Apr 14
Fall Sowing September 11 Sep 11 โ€“ Sep 25

Plant 0.5" deep ยท 2" apart ยท Rows 6" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February Direct Sow
March Direct Sow Harvest
April Harvest
May โ€”
June โ€”
July โ€”
August โ€”
September Fall Sowing
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

22โ€“35 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

255 days in Denton County

Growing Tips for Radish in Denton County

Direct sow Radish outdoors after March 10 in Denton County when soil has warmed and frost danger has passed.

With Denton County's clay soil (40% clay), work in 3-4 inches of compost before planting Radish. Avoid tilling when soil is wet to prevent compaction.

Your generous 255.0-day season in Denton County allows multiple plantings of Radish. Sow every 11.0 days for continuous harvest.

Common pests for Radish in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

With 64" of annual rainfall in Denton County, ensure good drainage for Radish โ€” excess moisture can promote root rot and fungal diseases.

General growing tips

Direct sow every 1-2 weeks for continuous harvest. Do not transplant. Harvest spring radishes promptly to prevent them from becoming pithy and hot.

Companion Planting

Good Companions

Avoid Planting Near

  • Hyssop

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Radish in Denton County, TX?

Denton County is in Zone 8a with an average last frost of March 10. Plan your Radish planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Denton County, TX?

Denton County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 10 and first fall frost is November 20.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Denton County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.

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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 Denton County, TX. Local conditions may vary. Last updated: April 2026.