How to Grow Tomatoes in Texas

Tomato plants (Solanum lycopersicum), typically grown as annuals, do well in sunny summer conditions, but not the withering heat that can strike central, western and northern Texas. Plant tomato seedlings as early in spring as possible in parts of the state with high summer temperatures, and choose varieties with early ripening times to beat the summer heat.

Cultivars to consider include:

‘Early Girl,' a determinate tomato plant that yields flavorful fruits in 65 days.

‘Celebrity,' a determinate plant that yields deep-red, medium-size fruits in 70 days.

‘Sun Gold,' an indeterminate tomato plant that bears yellow cherry fruits in 60 days.

Tomato fruits grow from clusters of flowers called trusses. Vinelike tomato plant cultivars and heirloom indeterminate tomato plants grow trusses on the sides of their stems, not their tips. Those plants grow more than 7 feet tall, requiring the support of wire cages or poles. They yield fruits over much of the summer growing season.

Determinate tomato plants grow as bushes, typically from 3 to 5 feet tall. They grow flower trusses on the tips of their stems and branches so stop growing taller. They yield a single robust harvest in a short period in late spring.

Tomato plants grow best when daytime temperatures are 70 to 85 degrees Fahrenheit. If nighttime temperatures are above 70 F and daytime temperatures are above 85 F, the plants drop their flowers, which are needed to set fruits; if blossoms don’t receive pollen, they can’t set fruits. Pollen becomes tacky and useless when daytime temperatures are above 85 F.

Plant tomato seedlings in a site exposed to full sun. Space plants grown on stakes or trellises 24 inches apart in rows that are 4 to 6 feet apart. Space caged tomato plants 6 feet apart with 6 feet between rows. Space dwarf varieties 12 to 18 inches apart with 2 to 3 feet between rows.

To plant tomato seedlings early enough for them to yield fruits before summer's heat, you may risk damaging them from drops in nighttime temperatures. Cover them with sheet plastic to protect them at night, but don't allow the plastic to touch them, and remove the plastic in the morning so they won’t become too hot.

If you anticipate spring heat, protect tomato plants with shade cloth, a netting available at many garden supply centers. The netting provides shade while letting air circulate. It typically comes in different mesh sizes to allow varying degrees of protection.

Test your garden's soil to determine which nutrients it may need. Soil testing kits are available from garden supply centers and county Cooperative Extension Service offices. Plan to fertilize 25 square feet of garden area for each tomato plant.

If your soil has not been tested, then incorporate 1 pound of 16-20-0 fertilizer at least 6 inches deep into 100 square feet of the soil.

Combine 1 level teaspoon of 30-10-10, water-soluble, granular fertilizer with 1 gallon of water, and pour at least 1 quart of the mixture at the bottom of each newly planted tomato seedling.

When you spot tiny tomato fruits on your plants, sprinkle 1 teaspoon of urea -- 45-0-0 fertilizer -- in a 6-foot-wide circle on the soil surface around each plant, and water it into the soil with 16 gallons of water.

Water tomato plants every three to four days. Give them enough water to keep the soil moist at least 3 feet from each plant's base. That should be at least 1 inch of water per week. One inch of water for a circle with a radius of 3 feet is about 16 gallons. Tomato plants need more water as they get larger and as heat increases.

To help maintain soil moisture in hot, dry weather, mulch the tomato plants' soil surface when the soil temperature reaches 70 F. Apply a 4- to 6-inch layer of grass clippings or clean wheat straw on the soil extending outward from 4 to 6 feet from the plants' stems. Do not allow the mulch to touch the stems.