Blog

When to Plant Watermelon in DeWitt County, TX

Watermelon
DeWitt County, Texas Zone 9a June

Top priorities for DeWitt County, Texas gardeners in June

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 2
Avg. first frost November 26
Soil temp (4") 83°F
Watering Low
Pest pressure High
Daylight 13.8 hrs
  1. Start harvesting watermelon

    If you can't use it all right away, check the food-preservation section of your planner.

Looking ahead to July
  • First harvests: watermelon

Instant PDF download. No spam, unsubscribe any time.

Watermelon is a sprawling vine crop that produces sweet, juicy fruits in hot weather. Varieties range from personal-sized icebox types to 50-pound giants.

DeWitt County, Texas is in USDA Zone 9a. The average last spring frost is March 2 and the first fall frost is November 26, giving you a growing season of approximately 269 days.

At an elevation of 1,649 feet, DeWitt County receives approximately 62.1 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Watermelon during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Watermelon root diseases.

DeWitt County, TX (Zone 9a) Long season
269 days
Last Spring Frost March 2
269 growing days
First Fall Frost November 26

DeWitt County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.8

Drainage

Well Drained

Watermelon Planting Risk Windows

Early Start (70% safe) ✓ Fits season (144 days to spare)
Start indoors: Jan 21 Transplant: Feb 25 🍅 Harvest: May 6 – Jun 24
Recommended (50%) ✓ Fits season (143 days to spare)
Start indoors: Feb 2 Transplant: Mar 9 🍅 Harvest: May 18 – Jul 6
Safe Start (90%) ✓ Fits season (137 days to spare)
Start indoors: Feb 25 Transplant: Apr 1 🍅 Harvest: Jun 10 – Jul 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 DeWitt County

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

Soil pH

Your soil pH (6.8–7.8) overlaps with Watermelon's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Watermelon.

Organic Matter

Organic matter is low (1.9%). Add 2-3 inches of compost before planting Watermelon.

How to Plant Watermelon

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Watermelon

4
successive plantings in your 269-day season

Sow every 8 weeks. Last sowing by Aug 18 to harvest before frost.

Watermelon Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
1.2″/week
Watering frequency 2-3 times/week
Season total 2,817 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Watermelon

Watermelon needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Watermelon Needs Rainfall You Supplement Action
Jan 1.8" 0" ❄️ Dormant
Feb 2.1" 0" ❄️ Dormant
Mar 6.5" 4" 2.5" 💧 Light watering
Apr 6.5" 5.9" 0.6" 💧 Light watering
May 6.5" 9.1" 0" ✅ Rainfall sufficient
Jun 6.5" 11.3" 0" ✅ Rainfall sufficient
Jul 6.5" 6.9" 0" ✅ Rainfall sufficient
Aug 6.5" 7.9" 0" ✅ Rainfall sufficient
Sep 6.5" 5.6" 0.9" 💧 Light watering
Oct 6.5" 3.7" 2.8" 💧 Light watering
Nov 6.5" 2.3" 4.2" 🚿 Regular watering
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in DeWitt County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Watermelon 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.

Watermelon needs ~1,551 GDD — county provides 4,909 GDD Excellent fit

Watermelon Planting Timeline — DeWitt County, TX

Watermelon Planting Calendar

Activity When Date Range
Start Indoors February 2 Feb 2 – Feb 16
Transplant Outdoors March 9 Mar 9 – Mar 23
Direct Sow March 2 Mar 2 – Mar 23
Harvest May 18 May 18 – Jul 6

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Transplant Outdoors Direct Sow
April
May Harvest
June Harvest
July Harvest
August
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

269 days in DeWitt County

Growing Tips for Watermelon in DeWitt County

Direct sow Watermelon outdoors after March 02 in DeWitt County when soil has warmed and frost danger has passed.

Common pests for Watermelon in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 3-4 weeks early or direct sow after soil is warm. Plant on mounds with plenty of space. Check ripeness by looking for a yellow ground spot and dull thump when tapped.

Recommended Watermelon Varieties for DeWitt County

Full-size melons that thrive with your long season

Crimson Sweet (85d) Charleston Gray (85d) Moon and Stars (95d)

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Watermelon in DeWitt County, TX?

DeWitt County is in Zone 9a with an average last frost of March 2. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.

What planting zone is DeWitt County, TX?

DeWitt County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 2 and first fall frost is November 26.

🌱

Your DeWitt County Garden Planner — Free

A 22-page printable planner built for DeWitt 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for DeWitt County, TX. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.