Watermelon in Zone 7B — Texas

Growing your own watermelon in Texas gives you access to fruit that's sweeter and more flavorful than anything you'll find in stores. Our long growing season and intense Texas heat create perfect conditions for these heat-loving vines, and there's nothing quite like cutting into a perfectly ripe watermelon that you've watched develop from a tiny seed in your own garden. You can even plant two crops here — one for summer harvest and another planted in late summer for fall picking.

Yes, watermelons need space and plenty of water, and our unpredictable weather can throw some curveballs their way. But with our 255-day growing season and the ability to plant from late March through mid-August, you have plenty of flexibility to work around Texas weather patterns. The key is choosing the right planting window and staying consistent with watering.

Starting watermelon seeds indoors isn't the preferred method, but it can give you a head start if you want to maximize your growing season or get around our sometimes unpredictable spring weather. Start seeds from late February through mid-March, about three weeks before you plan to transplant outside.

Use seed trays filled with quality seed-starting mix and keep them warm — watermelons need soil temperatures around 70-75°F to germinate well. Bottom watering works best to keep moisture consistent without disturbing the seeds. Place trays in a sunny window or under grow lights once seedlings emerge.

Handle watermelon seedlings very carefully since they hate root disturbance. Consider using biodegradable pots that can go directly into the ground, or be extra gentle when transplanting. With our early Texas spring, you'll have transplant-ready seedlings just as the soil warms up enough for outdoor planting.

Transplant watermelon seedlings outdoors from late March through late April, once soil temperatures consistently stay above 65°F and nighttime temperatures don't drop below 55°F. Your seedlings will need a full week of hardening off — gradually exposing them to outdoor conditions for longer periods each day.

Space transplants 6 to 8 feet apart in all directions since these vines spread extensively. Choose a sunny location with well-draining soil, and consider planting on small mounds to improve drainage and soil warming. Our spring weather can still surprise us with late cold snaps, so keep row covers handy for unexpected temperature drops.

Plant carefully to minimize root disturbance, water thoroughly after planting, and mulch around plants to conserve moisture. The combination of our variable spring rainfall and increasing heat means consistent watering becomes critical right from transplanting.

Direct sowing is the best method for watermelons in Texas since it avoids root disturbance and takes advantage of our naturally warming soil. Plant from late March through mid-August, with soil temperatures at least 65°F for good germination. The soil should feel warm to your hand when you dig down a few inches.

Prepare planting areas by working compost into the soil and creating slight mounds for better drainage and heat absorption. Plant seeds 1 inch deep and space them 6 to 8 feet apart — watermelon vines will easily fill this space and more. Plant 3-4 seeds per hill and thin to the strongest seedling once they're established.

For succession planting, you can direct sow every few weeks through mid-August to extend your harvest season. Later plantings will mature in fall when temperatures are more comfortable for working in the garden. Just remember that seeds planted during our hottest summer months will need consistent moisture and some shade protection during the most brutal heat.

Watermelons are thirsty plants that need consistent, deep watering throughout their growing season, especially during our hot Texas summers. They require about 1-2 inches of water per week, but you'll need to adjust based on our unpredictable rainfall — some years you'll get 50 inches, other years barely 15 inches. Check soil moisture with the finger test, pushing down 2 inches near the base of the plant.

During fruit development, these plants need the most water to support the growing melons. Water deeply at the base of the plant rather than overhead to reduce disease problems in our variable humidity conditions. Drip irrigation or soaker hoses work perfectly for this. When temperatures hit 97°F or higher (which happens regularly here), you may need to water every other day or even daily.

About 1-2 weeks before harvest, reduce watering to concentrate sugars and improve flavor — but don't let plants wilt completely. Our intense summer heat means the soil dries out faster than in cooler climates, so stay vigilant about moisture levels. A thick layer of mulch around plants helps retain soil moisture and keeps roots cooler during the worst of the Texas heat.

Watch for signs of stress: wilting during the hottest part of the day is normal, but if plants don't perk up by evening, they need more water. Yellowing leaves often indicate inconsistent watering, while cracked fruit means you've gone from drought to flood conditions too quickly.

Your first watermelons will be ready from mid-June through mid-November, typically about 85 days after planting. In Texas, this timing works perfectly since you can harvest before the worst heat or plant later for fall harvest when working conditions are more comfortable. Look for three key ripeness indicators: the ground spot (where the melon rests) turns from white to creamy yellow, the tendril nearest the fruit turns brown and dry, and the melon sounds hollow when you thump it.

Harvest in the morning when temperatures are cooler and handle fruit carefully — watermelons don't continue ripening once picked. Cut the stem with clean pruners rather than pulling to avoid damaging the vine. A ripe watermelon will feel heavy for its size and the surface will have a dull rather than shiny appearance.

Since watermelons don't ripen off the vine, timing is everything. Under-ripe melons will be pale, hard, and lack sweetness. Over-ripe ones develop a mushy texture and can split on the vine, especially after heavy rains that we sometimes get even during dry spells.

As first frost approaches in mid-November, harvest any remaining fruit even if they're not fully ripe — they won't survive freezing temperatures. Green watermelons can be used for pickles or preserves, making sure none of your garden space goes to waste.

Fusarium Wilt This shows up as wilting on one side of the plant first, then spreading throughout. You'll see yellowing leaves starting on one side, and if you cut open the stem, there are brown streaks inside. The soil-borne fungus persists for years and enters through roots, thriving in our warm Texas soil temperatures. Once infected, there's no cure — remove and destroy the entire plant immediately. Prevent it by choosing resistant varieties (look for 'F' on seed packets), rotating crops every four years, and raising soil pH above 6.5. Soil solarization works well in our intense summer heat.

Anthracnose Look for sunken, dark, circular spots on fruit, stems, and leaves. During our humid periods, you might see pink or orange spore masses on these spots. This fungal problem thrives in warm, humid conditions and spreads through rain splash — something we definitely get during our unpredictable storm seasons. Remove infected fruit and plant debris immediately, avoid overhead watering, and apply copper fungicide preventatively. Plant disease-free seeds and rotate your crops to break the cycle.

Poor Pollination Fruit that's small, misshapen, or fails to develop properly usually means pollination problems. Flowers might bloom but fall off without setting fruit, or you get lopsided melons. This happens when it's too hot or cold for pollinators to work effectively, or when male and female flowers don't overlap timing-wise. Our extreme heat can actually shut down pollination during the worst summer days. Hand-pollinate with a small brush during cooler morning hours, plant pollinator-attracting flowers nearby, and avoid pesticides during flowering.

Texas Specific Challenges Our combination of extreme heat, variable humidity, and unpredictable rainfall creates perfect storm conditions for watermelon problems. The intense summer heat stresses plants and can shut down pollination, while sudden heavy rains after dry periods can cause fruit splitting and fungal issues. Fire ants can also damage developing fruit, so monitor for ant activity around your melon patch.

Corn makes an excellent companion for watermelons since the tall stalks provide some afternoon shade during our brutal summer heat while the melons spread along the ground below. Radishes planted around the edges help deter cucumber beetles and other pests that commonly attack melons in Texas. Sunflowers work well too, offering height and attracting beneficial pollinators that watermelons desperately need during our hot summers when bee activity can slow down.

Avoid planting watermelons near potatoes since they compete for similar soil nutrients and space, plus potatoes prefer cooler conditions while watermelons thrive in our heat. The different watering needs also create problems — potatoes can rot with the heavy watering that watermelons require during Texas summers.