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Tomatoes Have Issues Too!

One of America’s most popular summer hobbies is growing tomatoes. But for all those millions who have participated in this annual summer ritual, there is always the potential heartbreak of insects or disease.

The first step to any solution is to diagnose the problem in a timely manner, which is why it is important to regularly monitor your tomatoes for pests and disease.

Insects that commonly attack tomatoes include tomato hornworms, whiteflies and aphids. Diseases that can infect tomato plants include early blight and blossom end rot. These are just some of the insects and diseases that can turn your summer garden from an adventure to a disappointment.

Tomato hornworms are large caterpillars that have horn-like protuberances. They feed on tomatoes, mercilessly stripping leaves from stems and eating unripe tomatoes. One way to reduce the possibility of hornworms is to loosely wrap a piece of aluminum foil around the lower few inches of the stem, at the ground, to prevent hornworms from crawling up. Once hornworms attack, they can be removed by hand or controlled by insecticides.

Aphids and whiteflies are insects that both cause tomato leaves to turn yellow. Both leave a telltale secretion called honeydew, making the tomato plant leaves sticky and shiny. Small infestations will not cause significant problems, but larger infestations may require insecticidal soap to bring them under control.

Besides insects, tomato plants may develop one of several common diseases. One of the more common is early blight, whose symptoms become more obvious as the temperatures become hotter. This fungus causes large dark spots on older leaves, but can sometimes spread to stems and fruit. Leaves may turn yellow and drop. This fungus can be spread by overhead irrigation or planting too closely. It is imperative to remove all diseased plant material and throw it in the trash as the fungus can over-winter and withstand the heat of compost piles. Good garden sanitation and crop rotation are the best controls.

Blossom end rot begins as light brown, watery sores on the blossom end of the fruit. These sores grow larger and turn black and leathery. It is generally thought that a combination of excessive temperature and water fluctuations cause blossom end rot. When these circumstances occur at the same time, the plant may develop a calcium deficiency during fruit formation. To prevent blossom end rot, try to provide consistent moisture, mulch to reduce moisture fluctuations, and avoid planting until there is no possibility of frost and daytime temperatures are at least in the 60s.

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