Of all the vegetables you can plant in a Texas garden, tomatoes are one of the easiest to grow. The vine is heat tolerant, adapts to a wide variety of soil and produces fruit from early summer until the first frost in fall. In deep southern Texas where frost is rare, the plant may be treated as a perennial. But even with a tomato's versatility, proper care is still important to ensure that your tomato plants thrive and produce an abundant crop.
Select a site with full sun and well-drained soil. Tomato plants do not like to be planted in waterlogged dirt. Have the soil of your garden tested by a company that specializes in soil analysis. The Texas A&M University operates a soil-testing laboratory that will analyze your soil and make recommendations for what amendments you should add to improve the soil. You can download a copy of a soil submission form and instructions for taking soil samples (see Resources below)
Improve the drainage of your soil and work organic material such as compost and peat moss into the soil several months before you plant your tomatoes. To do so, loosen the soil to a depth of 8 to 12 inches with a rototiller. Then spread a mixture of one part compost and one part peat moss over the soil to a depth of 4 inches. Add gypsum to break up heavy clay soil according to the directions on the gypsum package. Mix these amendments into the soil by pushing a rototiller over the soil again.
Select varieties of tomato that are tolerant to heat, such as super fantastic or Porter pink. Most tomatoes thrive in temperatures up to 90 degrees. But parts of southern Texas may exceed temperatures of 100 degrees during July, August and September.
Remove all but the top two leaves from the tomato plant. Then dig the tomato planting hole deeply enough that the root ball and the bottom two-thirds of the stem is buried. Remove the tomato plant from its seedling pot by placing it on its side. Support the stem in one hand so it will not break and gently tap the side of the pot to dislodge the root ball. Place the root ball in the hole and cover with soil. Bury the plant's rootball and two-thirds of the stem. Space your tomato plants 3 feet apart to promote air circulation.
Water your tomatoes deeply once per week. Mulch around the stem with an inch of finished compost. Surround your tomatoes with companion plants that drive away predators such as Japanese beetles and cutworms. Companion plants with bug-repellent properties include garlic, basil and marigolds.
Enclose your tomatoes with a tomato cage to support them as they grow larger. This will keep them from touching the ground and causing fruit to rot.