Tomatoes are the most popular crop for home gardeners, but it can be a challenge to grow them in Texas. One of the biggest problems that Texas tomato gardeners face are pests. The best way to battle a garden pest problem is by being vigilant, proactive and consistent in controlling it. Being able to identify pests immediately will help you take quick action.
Aphids and Whiteflies
Aphids are tiny insects that can be black, white or green, which can often be found on the stem or leaf of the plant. Whiteflies are white, but attack plants the same way. Treat these insects immediately as their population will grow quickly.
A blast of a hose will usually be successful in removing a few aphids or whiteflies at first sight of them. Applying insecticidal soaps or hot pepper sprays will further help repel them. If only a few plants are being infected, they should be removed and destroyed.
Drawing beneficial insects to your garden, such as ladybugs, praying mantises and lacewing flies, will help keep the population of these damaging insects down. These beneficial insects are attracted to marigolds, catnip and lemon balm, so planting these herbs near tomatoes will help. You can also purchase the larvae of these insects at some gardening supply stores.
If you come out to check your tomato seedlings one morning to find the plants lying on the soil as though they've been snipped at the soil line with a pair of dull scissors, you probably have cutworms. Nocturnal cutworms curl around the stem at or just below the soil line and cut right through, sometimes decimating an entire row of plants in a single night. If cutworms have been a problem in your garden, plow and furrow your field in the summer and fall to destroy eggs and larvae.
Apply soil insecticides when preparing your bed in the early spring. To be on the safe side, you can wrap some cardboard or aluminum foil as armor around your tomato stem's base, and slightly below the soil line, to thwart these ruthless pests.
Leaf Miners and Pinworms
Leaf miners are tiny fly larvae that tunnel through leaves, munching away at the tissue, and can usually be spotted by the tracks they leave in the green leaves. While a few leaf miners don’t do major damage, too much can destroy the leaf enough to interfere with photosynthesis. If leaf miners are left to grow, they become pinworms and crawl out of the leaf to continue feasting on the plants, as well as the fruits.
Pinworms are brown in color and grow up to 1/4 inch long. Younger plants will suffer more from leaf miner damage than established plants, but pinworms can do serious damage to established plants and fruits. If you see just a few leaf miner tracks, snip off the leaves and destroy them. If you find pinworms, chances are the problem is already out of control. Apply an insecticide to prevent further problems. Dispose of plants that are lost causes.
These caterpillars, which grow up to four inches long, are usually green, sometimes with white stripes, and have a little horn growing out of the front of their heads. The devilish pests feed on both the foliage and the fruit of the tomato plants.
One single hornworm can destroy a plant quickly. Controlling tomato hornworms with natural methods is the most effective measures you can take. Examine your plants carefully and pick them off by hand to destroy them. Birds keep the tomato hornworm population at a minimum, so keep a birdbath near your plants.
Braconid wasps can be attracted to your garden by planting coriander, marigolds or masterwort near your tomatoes, or by purchasing them from gardening centers that sell live beneficial insects. These wasps lay eggs on the hornworm that turn into parasitic larvae. If you see hornworms with what looks like white rice stuck to their back, leave them alone, as these are the wasps that will eventually destroy the population.