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Problems with Tomato Plants

The information you will find here primarily discusses the most common problems with tomatoes, brought to us by customers in the spring and throughout the growing season.

Physiological Disorders

Caused by the interruption of basic requirements of natural plant growth, which can range from “too much” to “too little.” Factors include air temperature, moisture, and nutrients. This type of stress can be the catalyst for plant, bloom, or production problems.

Blossom-End Rot
Usually associated with calcium deficient soils, blossom-end rot can also be caused by a sudden change in soil moisture, especially when a dry heat wave with temperatures above 90 degrees Fahrenheit follows the rapid growth period of the plant. Blossom-end rot manifests as a black, rotten spot on the blossom side of the fruit at any stage of growth.

Blossom Drop
After the flower appears, it takes about 50 hours to determine whether or not it has been fertilized and will set fruit. If temperatures are too low, or too high, it will take longer to pollinate and the flowers will fall off. Note: pollen is most readily available between 10 a.m. and 4 p.m.

Growth Cracks
These usually occur during periods of rapid fruit growth, when a wet period sets in after a dry period. Essentially, the inside grows faster than the outside skin.

This is a common problem in the South, and it usually occurs with green fruit. The sunscald usually appears on the sun-facing side as a white, paper-like surface.


These insects are very simple to identify, swarming in masses whenever you touch the plant. They feed on a plant’s foliage and secrete a sticky substance on leaves and fruit, which soon develops into a sooty mold. Heavy infestation of whiteflies can cause death to a plant. In a 30-day period, all growth stages of this insect may be present, and most control products will not deter insects at every stage.

These insects are very common and relatively easy to control. Aphids may be pale green to red in color, and usually feed on new growth.

These worms attack at the soil level, usually at night. To control cutworms, make a collar out of a small drinking cup by tearing the bottom out. Place the collar around the base of the stem, making sure it is pushed down into the soil at least a half-inch (1/2 inch) deep to deter cutworms.

These worms can devastate foliage and fruit. Hornworms are extremely difficult to distinguish, as their bodies are perfectly matched to the color of the foliage. Dipel or BT products are very effective for controlling Hornworms.


Information on diseases affecting tomatoes is forthcoming. Please check back to this page soon for updates.