If you are seeing blooms that later fall off without producing the tomato, then your blooms are not setting. This is most often caused by the weather. Rapid temperature changes are typical of Texas weather and especially prevalent the last two springs. Large variety tomato blossoms only set within a narrow temperature range. Use Bonide Tomato and Blossom Set Spray on each bloom and surrounding foliage.
If your blooms are not falling off then your plant may not be seeing any bee action. The bee population is declining and it is vitally important that you encourage the presence of bees in your yard. Plant flowers that attract bees such as Pentas, Purslane, Bee Balm, and Butterfly Bushes. Also avoid insecticides that are harmful to bees. The labels will say what they control and what they don't. More immediately, you can spread pollen among your blooms by hand. Tomatoes are self pollinating so all you really need to do is flick the blooms to shake the pollen around. If you have more plants, you can also cross pollinate with a paint brush or makeup brush. Gently spin the bristles around inside each bloom in a striped pattern across the plants.
If you're not seeing any blooms at all but your plant looks otherwise full and healthy, it's possible you're not getting enough sun. All veggies need full sun for the majority of the day to bloom.
Why are my tomato leaves turning yellow, dying, or shriveling up?
If your leaves are turning mottled yellow from the bottom of the plant up, it's likely that you have spidermites. A very common problem in North Texas. You should see webbing and the bugs themselves are almost microscopic. Thump the leaves over white paper to find them. Bring a leaf in to be sure but if it is spidermites, you can treat with Hi Yield 55% Malathion Spray or Natural Guard Insecticidal Soap.
If your leaves are turning bright yellow from the bottom up, it could be a fungal problem. Again, bring a leaf in to be sure. If it is fungus, you can use Fertilome Broad Spectrum Lawn and Garden Fungicide or Hi-Yield Bordeux Mix Fungicide.
If your leaves are rolling up or wilting, it is likely caused by the heat. It's completely normal for plants you are saving over the summer for a second fall harvest to show a little strain. Just make sure you're not over or under watering and wait it out.
