Gardening in South Texas feels like being in a tropical paradise. While people in North Texas are often worried about ice and snow, gardeners in the south are usually enjoying sunshine and warm breezes.
According to the 2023 USDA Plant Hardiness Map updates used for the 2026 growing season, South Texas has moved even further into the warm zones. Most of this region is now in Zone 9 or even the very tropical Zone 10.
This means the Texas growing season almost never stops, and you can grow plants here that would never survive a winter in Dallas.
The Tropical Zones of South Texas: 9a, 9b, and 10a
South Texas is split into three main zones that indicate how warm it stays in winter. These zones, which are 9a, 9b, and 10a, are shaped by the warm water of the Gulf of Mexico.
Much like the humid air in Houston, the climate here is very moist and stays warm even at night. This subtropical climate is ideal for plants that thrive in warm conditions, but it also means the summer sun can be exceptionally intense.
Because this region is so far south, it acts like a bridge between the brush country and the ocean.
Gardening in the Brush Country: Zone 9a and 9b
The northern and middle parts of South Texas, including Laredo, Corpus Christi, and areas near San Antonio, fall into Zone 9. In Zone 9a, winter temperatures stay between 20°F and 25°F, while Zone 9b is even warmer, staying between 25°F and 30°F.
The soil here can be a mix of heavy clay and sandy loam. This is a great place to grow Texas Superstar plants, such as esperanza and hibiscus. These plants love the long summers and rarely suffer from the very short winters.
The biggest challenge in Zone 9 is ensuring plants get enough water during the dry spells between rainstorms.
The Tropical Tip: USDA Zone 10a
As you move to the very bottom of the state, in the Rio Grande Valley near Brownsville and McAllen, you enter Zone 10a. This is the warmest part of the entire state, where winter temperatures rarely dip below 30°F to 35°F.
This area feels much warmer and more tropical than the hills of Austin. The soil here is often very rich and fertile, which is why it is famous for growing Ruby Red grapefruit and oranges.
In Zone 10a, you can grow true tropical plants like tomatoes, bougainvillea, papaya trees, and many types of palms that would freeze anywhere else. The only real winter task here is occasionally covering your most sensitive tropicals if a rare cold front moves in.
Success in the South Texas Sun
The secret to a great South Texas garden is protecting your plants from the midday sun. Since the last frost usually happens very early, sometimes as early as February, you can start your spring garden while the rest of the state is still cold.
Because the sun is so strong, a thick layer of mulch is essential to retain moisture in the ground. Also, many gardeners here use shade cloth to give their vegetables a break from the afternoon heat.
If you focus on plants that love the sun and can handle the humidity, your South Texas garden will be lush and colorful all year long.
What Planting Zone Is Southeast Texas?
Most of Southeast Texas, including places like Beaumont, Port Arthur, and the areas surrounding Houston, now falls into Zone 9a and Zone 9b. In these zones, it rarely gets colder than 20°F to 25°F in the winter.
This is much warmer than the chilly nights in North Texas. Because the Gulf of Mexico is so close, the salt air and high humidity act like a warm blanket, protecting your plants from the harsh freezes that happen further inland in Central Texas.
Grid
What Is the Planting Zone for Texas? Zone 6b to 10a
What Planting Zone Is South Texas? Zone 9 and 10
What Planting Zone Is West Texas? Zone 7, 8 and 9
What Planting Zone Is East Texas? Zone 8a, 8b, 9a
What Planting Zone Is Central Texas? Zone 8b and 9a
