When To Plant Watermelons In Texas

If you’re planning to grow watermelons in Texas, timing is everything. Knowing exactly when to plant watermelons in Texas is the first and most important step to a successful harvest.

Get it right, and you’ll be rewarded with sweet, juicy fruit. Plant too early or too late, and you might face frost, disease, or disappointing melons. Let’s break down the optimal schedule for your region.

Texas is a big state with several distinct climate zones. Because of this, there is no single calendar date that works for everyone. Your planting window depends heavily on where you live. The key is to wait until all danger of frost has passed and the soil has warmed up sufficiently.

Understanding Texas Growing Zones

Your USDA Hardiness Zone is a great starting point. It tells you the average last frost date in your area. Watermelons are very sensitive to cold and will not survive a frost. They also need warm soil to germinate and grow.

North Texas (Zones 7a-8a): This includes cities like Dallas and Fort Worth. Your last frost is typically around late March to mid-April. The optimal planting time here is from early April to mid-May.
Central Texas (Zones 8a-8b): This covers Austin, San Antonio, and the Hill Country. Frost danger usually ends by mid-to-late March. Aim to plant from late March through April.
South Texas & Coastal Plains (Zones 9a-10a): This region, including Houston, the Rio Grande Valley, and Corpus Christi, has a very long growing season. You can often plant as early as February or March. A second, fall planting in July or early August is also possible.
West Texas & Panhandle (Zones 6b-7b): Areas like Amarillo and Lubbock have a shorter season and later frosts. Wait until May to ensure the soil is warm enough.

The Soil Temperature Rule

No matter your zone, always check your soil temperature. This is a non-negotiable step for good germination. Use a soil thermometer.

Plant seeds or transplants only when the soil at a 4-inch depth is consistently at least 70°F.
Ideally, wait for it to reach 75-80°F for fastest growth. Seeds will rot in cool, damp soil.

Starting Seeds Indoors vs. Direct Sowing

You have two main options for getting your plants started. Each has it’s pros and cons.

Starting Seeds Indoors

This gives you a head start, especially in regions with a shorter warm season.

Start seeds indoors about 3-4 weeks before your planned outdoor transplant date.
Use biodegradable pots to avoid disturbing roots. Watermelon seedlings don’t like being transplanted.
Provide plenty of light and keep them warm until it’s time to move them outside.

Direct Sowing in the Garden

This is often easier and is recommended where the season is long enough.

Wait for the correct soil temperature (70°F+).
Plant seeds 1 inch deep in small mounds or hills. Space them about 2 feet apart in the row.
Rows should be 5-6 feet apart, as vines need lots of room to spread.

Step-by-Step Planting Guide

Once your date and method are set, follow these steps for healthy plants.

Choose the Right Variety: Pick types suited for Texas heat. ‘Crimson Sweet’, ‘Charleston Gray’, ‘Black Diamond’, and ‘Sugar Baby’ (a smaller icebox type) are all excellent, reliable choices.
Site Selection: Watermelons need full sun—at least 8 hours of direct sunlight daily. More is better.
Soil Preparation: They prefer loose, well-draining soil rich in organic matter. Work in several inches of compost or aged manure before planting. A soil pH between 6.0 and 6.8 is ideal.
Planting: For seeds, plant 4-6 per hill, later thinning to the 2-3 strongest seedlings. For transplants, set them at the same depth they were in their pot and water them in thoroughly.
Initial Watering: Keep the soil consistently moist (but not soggy) until seeds germinate and seedlings are established.

Caring for Your Watermelon Plants

Proper care after planting ensures strong vines and good fruit set.

Watering

Watermelons have deep roots but need consistent moisture, especially during fruit set and growth.

Water deeply and less frequently to encourage deep rooting. Aim for 1-2 inches per week.
Use soaker hoses or drip irrigation to keep foliage dry and prevent disease.
Reduce watering significantly during the last week or two before harvest. This concentrates the sugars for sweeter fruit.

Fertilizing

Feed your plants appropriately for vigorous growth.

At planting, use a balanced fertilizer (like 10-10-10).
When vines begin to run, switch to a lower-nitrogen, higher-phosphorus and potassium fertilizer to promote flowering and fruiting.
Avoid over-fertilizing with nitrogen, which leads to lots of leaves but few melons.

Weeding and Mulching

Keep the area around young plants weed-free. Once vines spread, they will shade out most weeds. Applying a thick layer of straw or organic mulch helps retain soil moisture, suppress weeds, and keep the developing fruit clean and off the bare soil.

Common Texas Growing Challenges

Being prepared for these issues will save you alot of hassle.

Heat Stress: Extreme Texas heat can sometimes cause pollination problems. Ensure plants have adequate water during heatwaves. Shade cloth during the hottest part of the afternoon can help in extreme cases.
Pests: Watch for aphids, cucumber beetles, and squash vine borers. Use row covers early in the season, and inspect plants regularly. Spider mites can be a problem in hot, dry weather; a strong spray of water can dislodge them.
Diseases: Fungal diseases like powdery mildew and fusarium wilt can occur. Choose resistant varieties when possible, avoid wetting foliage, and practice crop rotation (don’t plant melons in the same spot year after year).

How to Tell When Watermelons Are Ripe

Harvesting at the right time is crucial. Here are the classic signs:

The Curly Tendril: Look at the curly tendril on the stem nearest the fruit. When it turns completely brown and dry, the melon is usually ripe.
The Ground Spot: The underside of the melon (where it rests on the ground) changes from white or pale green to a creamy yellow.
Sound: Thump it. A ripe watermelon will have a deep, hollow sound. An unripe one sounds tight and high-pitched.
Sheen: The rind loses its glossy shine and becomes dull.

Use all these clues together for the best judgement. Once picked, watermelons do not continue to ripen further.

FAQ: Planting Watermelons in Texas

What is the latest I can plant watermelons in Texas?
In most of Texas, aim to have seeds in the ground by late June to early July at the absolute latest. This gives enough time for fruit to mature before cooler fall temperatures arrive. South Texas can plant later for a fall crop.

Can I grow watermelons in pots?
Yes, but choose a compact or “bush” variety and use a very large container (at least 20 gallons). Ensure it has excellent drainage and be prepared to water frequently.

How long do watermelons take to grow?
Most varieties need 80-100 days from planting to harvest. Check the “days to maturity” on your seed packet. Smaller types like ‘Sugar Baby’ mature faster (around 75 days).

Why are my watermelon plants flowering but not producing fruit?
This is often a pollination issue. The first flowers are male and do not produce fruit. Later, female flowers (which have a tiny melon at the base) appear. If bees aren’t active, you can hand-pollinate them using a small paintbrush to transfer pollen from male to female flowers.

Is it to late to plant if I missed the spring window?
In South and Central Texas, you can try a second planting in early July for a fall harvest. Just be mindful of extreme late-summer heat on young seedlings. Provide some afternoon shade if needed.

By following this Texas-specific timing and care guide, you’ll give your watermelon plants the best possible start. Paying attention to your local frost dates and soil temperature will set the stage. With proper watering, feeding, and a little patience, you’ll be well on your way to harvesting your own sweet, homegrown watermelons this season.