Backyard gardeners favor growing tomatoes over all other types of vegetables, according to Washington State University. No wonder, since the plants are relatively easy to care for and produce lots of juicy fruit. Unfortunately, even the best-maintained tomato plant can sometimes experience various health problems that affect both plant growth and fruit production.
Late blight is a fungal disease that's common in moist growing climates like the Pacific Northwest and causes wilting of the foliage. It is most common in the late summer when the combination of warmth and moisture creates the perfect environment for fungal growth. Gardeners can reduce the risk of late blight by keeping the tomato plant's foliage dry, only watering it at its base instead of on its leaves. For serious blight problems, apply an organic copper spray or standard fungicide, according to Washington State University.
Blossom-end rot causes rotting of the bottom portion of the tomato fruit. Though it's unaesthetic and results in fruit loss, it is rarely a serious disorder, according to the University of New Hampshire. The problem typically arises because of overuse of a high-nitrogen fertilizer or poor soil moisture. Rotting usually resolves itself after the gardener begins fertilizing properly with a low-nitrogen garden fertilizer and maintaining adequate soil moisture with regular waterings and a layer of mulch.
Psyllids are an insect pest that commonly attacks tomatoes in states like Colorado. Symptoms include widespread yellowing of the tomato foliage and the presence of the yellow or white bugs on the underside of the tomato leaves. Dust the entire tomato plant with a sulfur-based plant powder to kill off the psyllids.
Tomatoes can get sunburned, and the result is a yellow or white patch on the part of the tomato that's facing the sun. The problem is not lethal, nor contagious. The University of New Hampshire recommends against pruning tomatoes, since this removes the foliage needed to protect ripening tomatoes from excessive sunlight.
Stinkbugs are more than just smelly insects; they also feed on the tomato fruit, leaving ugly scars that cause the fruit to rot. Weeds usually play host to the stinkbug. Gardeners who maintain a wide weed-free space around their vegetable garden will minimize their chances of a stinkbug invasion. Heavy insect infestations can be treated with a carbaryl-based insecticide that's formulated for vegetable garden usage.