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Tomatoes: Disease and Drought

Tomatoes: Disease and Drought

Tomato plants are susceptible to foliar diseases and sensitive to drought.  To avoid those problems, gardeners need to use extra care in the garden.

Selecting a disease resistant tomato variety is one of the first steps toward growing healthy tomato plants. There are plenty of good tomato varieties, but it’s best to pick a variety recommended for your region. To be sure the variety you select has resistance to Verticillium wilt, Fusarium wilt, and Root-knot nematodes, look for theletters, “V,F&N’’ accompanying the variety name.

Hunter McBrayer. an Alabama Extension urban regional agent,  said disease on tomatoes in Alabama is almost a certainty.

“Delaying or reducing the effect of disease on tomato plants can be done through integrated pest management,” he said. “Start with healthy plants. Do not buy plants from your local nursery or garden center that look ‘sick.'”


Plants should be sprayed with fungicides beginning when the plants are eight to 10 inches tall. Continue spraying every seven to 10 days, or as suggested on the manufacturer label. It is important to remember tomato plants are constantly putting on new growth, and that light and heat destroy fungicide chemicals making the continuous applications a necessity.

Adding insecticides to the fungicide can be an option to control specific insect issues. Before purchasing an insecticide, properly identify the pest on tomato plants. If there is uncertainty, contact a local Extension agent for a recommendation. Like fungicides, insecticides should be applied according to the directions on the label. The best defense against tomato pests is to apply treatments while insects are small.

McBrayer said applying a layer of mulch around the base of tomato plants could also help ward of disease.

“Many fungi have spores that live in the soil and splash up to the bottom leaves,” he said. “A layer of mulch will block that from happening as well as regulating heat and moisture around the plants, thus reducing stress.”


Tomato plants are also very susceptible to drought problems.shutterstock_109356128

McBrayer said the mulch serving as a barrier from disease can also help lock moisture into the soil.

“Mulching helps regulat the moisture in the sil and can help with blossom end rot,” he said. “Blossom end rot is caused by a calcium deficiency in the developing fruit. Needed calcium cannot be moved without water.”

When drought-stressed plants are irrigated or it rains after a prolonged period of time, mature fruits will likely crack. In this case green, pink and ripe tomatoes should be promptly picked from drought-stressed plants.

Check out Alabama Extension’s Backyard Tomato Production for more information and ideas to boost your tomato growing skills.

To learn more about how to enhance your garden and landscape, check out Alabama Extension’s “Gardening in the South” series. You can find the series on iBooks.

Based on proven Master Gardener training and seasoned with university research, the “Gardening in the South” series of books is packed with information, tips and tricks to being a successful Southern gardener.

Have a gardening question? Call the Master Gardener Helpline. To reach the helpline, dial 1-877-252-GROW (4769).

About Katie Nichols


  1. do you have just basic recipes for cooking greens and beans ahd do you have extension classes on canning like some of the other states have?