Gardening Problems: I Have a Hanging Tomato Plant That Is Losing Its Leaves & Dropping Blossoms

Early Blight

• Caused by the fungus Alternaria solani, early blight is a devastating foliar disease that affects tomatoes and other common garden vegetables. Early blight causes 1/2-inch circular lesions to appear on the foliage of affected plants. As the disease progresses, infected leaves wither, die and drop from the plant. In addition to defoliation, tomato plants infected with early blight may experience other cultivation complications, such as stem cankers, fruit rot and collar rot.

Early Blight Controls

• Once a tomato plant is infected with early blight, the disease can be difficult, if not impossible, to control. Prevention through careful cultivation practices are a home gardener's best defense against fungal diseases such as early blight. The University of Maine Cooperative Extension recommends selecting disease-resistant tomato cultivars and irrigating them early in the morning to ensure that their foliage is completely dry before nightfall. Treat plants with a preventative fungicide, such as chlorothalonil, every seven to 10 days to help avoid early blight infection. Plants infected with early blight should be destroyed at the end of the growing season to prevent the spores from spreading and infecting other plants.

Blossom Drop

• In tomato plants, blossom drop isn't caused by disease or poor cultivation practices, but by unsuitable temperatures. Tomato plants need nighttime temperatures between 55 and 75 degrees Fahrenheit in order to set healthy fruit. Prolonged exposure to nighttime temperatures that are too warm or too cool will cause your tomato plants to drop their blossoms before they have had a chance to set their fruit.

Blossom Drop Controls

• Though tomato blossom drop is caused by unsuitable temperatures, there are still a couple of things that home gardeners can do to prevent or minimize the problem. The Alabama Cooperative Extension System recommends that gardeners in unsuitably warm climates select "heat set" or "heat tolerant" tomato plant cultivars to avoid blossom drop. In suitably cool climates, blossom drop can be prevented by spraying tomato plants with a blossom-set hormone spray, applied according to package directions.