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When to Plant Radish in Grimes County, TX

Grimes County, Texas Zone 9a May

Grimes County, Texas gardeners: here's your May plan

A quick May briefing for Grimes County, Texas gardeners — what's urgent, what's next, and what can wait.

Avg. last frost February 25
Avg. first frost December 1
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 13.5 hrs

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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.

Grimes County, Texas is in USDA Zone 9a. The average last spring frost is February 25 and the first fall frost is December 1, giving you a growing season of approximately 279 days.

At an elevation of 33 feet, Grimes County receives approximately 65.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 91°F, providing good warmth for Radish during the growing season. Sandy soil warms quickly in spring — great for early planting — but Radish will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Radish root diseases.

Grimes County, TX (Zone 9a) Year-round
279 days
Last Spring Frost February 25
279 growing days
First Fall Frost December 1

Grimes County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.8-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (234 days to spare)
Transplant: Feb 12 🍅 Harvest: Mar 12 – Apr 2
Recommended (50%) ✓ Fits season (230 days to spare)
Transplant: Feb 25 🍅 Harvest: Mar 25 – Apr 15
Safe Start (90%) ✓ Fits season (233 days to spare)
Transplant: Mar 11 🍅 Harvest: Apr 8 – Apr 29

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 Grimes County

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

Soil pH

Your soil pH (5.8–6.5) overlaps with Radish's range (6.0–7.0), though not a perfect match.

Soil Texture

Sandy soil in Grimes County warms quickly in spring but drains fast. Radish will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Radish.

Organic Matter

Organic matter is low (1.7%). Add 2-3 inches of compost before planting Radish.

How to Plant Radish

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Radish

16
successive plantings in your 279-day season

Sow every 2.4 weeks. Last sowing by Oct 27 to harvest before frost.

For a dedicated fall crop, sow by Oct 06.

Plant Water Budget

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

Water stress score is 6/10 — 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 1.9" 0" ❄️ Dormant
Feb 2.2" 2.1" 0.1" 💧 Light watering
Mar 2.2" 4.7" 0" ✅ Rainfall sufficient
Apr 2.2" 6" 0" ✅ Rainfall sufficient
May 2.2" 9.9" 0" ✅ Rainfall sufficient
Jun 2.2" 9.9" 0" ✅ Rainfall sufficient
Jul 2.2" 8.3" 0" ✅ Rainfall sufficient
Aug 2.2" 8.3" 0" ✅ Rainfall sufficient
Sep 2.2" 6.6" 0" ✅ Rainfall sufficient
Oct 2.2" 3.9" 0" ✅ Rainfall sufficient
Nov 2.2" 2" 0.2" 💧 Light watering
Dec 2.2" 1.7" 0.5" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in Grimes County). Supplement amounts are based on average rainfall — 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" — 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.

Radish needs ~520 GDD — county provides 5,110 GDD Excellent fit

Radish Planting Timeline — Grimes County, TX

Radish Planting Calendar

Activity When Date Range
Direct Sow February 4 Feb 4 – Feb 25
Harvest March 4 Mar 4 – Mar 25
Fall Sowing October 6 Oct 6 – Oct 20

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

22–35 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

279 days in Grimes County

Growing Tips for Radish in Grimes County

Direct sow Radish outdoors after February 25 in Grimes County when soil has warmed and frost danger has passed.

Sandy soil in Grimes County dries quickly — mulch Radish with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Summer highs in Grimes County reach 91°F — grow Radish as a spring or fall crop. Use shade cloth if planting in summer.

Your generous 280.0-day season in Grimes 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.

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 Grimes County, TX?

Grimes County is in Zone 9a with an average last frost of February 25. Plan your Radish planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grimes County, TX?

Grimes County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 25 and first fall frost is December 1.

🌱

Your Grimes County Garden Planner — Free

A 24-page printable planner built for Grimes County (Zone 9a). 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 Grimes 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.