The most common tomato plant problems are diseases, insects and environmental issues. Growing tomatoes from tomato seedlings into healthy tomato plants requires an understanding of what issues may affect the vegetable garden and how to avoid tomato pests.
Diseases are the most frustrating of the tomato plant problems because there is often no treatment. Successful tomato cultivation will include observing the plants from tomato seeds through harvest. Fungi that are transmitted through the soil such as Fusarium and verticillium damage the stems and cause the stems to become discolored. When the stem becomes damaged, nutrients are not carried to the upper part of the plant, which causes the plant to wither and die. There is no treatment, so it is important to buy resistant varieties.
Other types of disease that can cause tomato plant problems are the tomato spotted wilt virus and tobacco mosaic virus. The tomato spotted wilt virus is spread by the thrip, and it causes cankers to develop on the tomato and the leaves and stems to die back. Since there is no cure, the infected plants have to be removed from the garden and thrown away. The tobacco mosaic virus is usually spread by gardeners who smoke or have come into contact with tobacco. To prevent, gardeners should wash their hands before handling any plants.
Insects also contribute to tomato plant problems either through carrying diseases or eating the plants. Horn worms are a type of caterpillar that eats the foliage. They are typically three to four inches long and easily noticeable. Simply removing them from the infected plant often is sufficient. Another type of insect that eats the leaves is a flea beetle. The best way to rid your plants of this insect is to wipe down the leaves with soapy water.
Juice-sucking insects such as aphids and psyllids also create tomato plant problems. Both are found on the underside of leaves, causing the plants to be stunted. If the infestation is severe, no tomatoes will form. To rid infected plants of aphids or psyllids, an insecticidal soap can be used.
Environmental issues are the most common tomato plant problems and also the easiest to control. Blossom end rot, which causes the bottom of ripening tomatoes to turn black, shrivel up, and rot, is caused by insufficient calcium during development. Keeping the tomato plant watered at regular intervals and not allowing prolonged dry spells usually prevents blossom end rot.
Growth cracks are another environmental issue that can be easily controlled. Growth cracks can form a circular pattern on the top of the tomato or form deep fissures running vertically from the stem to the base. Both are caused by an initial over watering or heavy rain period followed by lack of watering that resulted in the plant's growth being stunted. To prevent this, the plants should be watered regularly and not allowed to get over watered.
