While planting a home vegetable garden ultimately results in a harvest if fresh produce for your dinner table, getting from seed to salad may require gardeners to identify and control disease. Vegetable gardens are susceptible to many diseases ranging from root rot to cankers to leaf blight. The chance of disease is greatly reduced by taking preventative measures, according to University of Missouri Extension, including selecting a good site, planting resistant cultivars, tilling soil between plantings, and keeping your garden clean and free of debris.
Foliage on vegetables is susceptible to many diseases, including powdery mildew, leaf blight and leaf spots. Each of these diseases has a different cause, but all are treatable. When a plant suffers from powdery mildew, it appears as if baby powder is on the leaf. Leaves may be treated with sulfur when mildew appears with a follow-up treatment 10 days later.
Leaf blight is a bacteria that leaves watery-looking spots on leaves and may be treated with an application of fixed copper while leaf spots are caused by fungus and appear as brown or black spots. Leaves may be treated with a fungicide.
Vegetables, particularly those growing above ground, are susceptible to a variety of diseases, including anthracnose and fruit rot. Anthracnose presents itself as sunken spots on vegetables and may be treated with a fungicide. Vegetables with fruit rot or blossom-end rot will have soft black spots. This may be an indication that soil is calcium deficient or that the plant is not getting adequate water.
Among the most common stem diseases are stem blight and cankers, which are open sores that may be symptoms of "Black Leg." The key symptom of stem blight is a crack in the stem that is seeping a puss-like substance. Stem blight is a fungus and may be treated with an application of fungicide.
The roots of vegetable plants are susceptible to root rot and root-knot nematode, either of which could kill the plant if not treated properly. Plants with root rot will have dark red sores on the lower stem and roots and, if untreated, the roots will die. To avoid root rot, crops should be rotated, but if plants develop this disease, they may be treated with PCNB fungicide.
Plants with root-knot nematode will have a swollen root system caused by small worms that feed on the stem and roots. There are no remedies for this disease for home gardens, but rotating infected plants with resistant varieties should lower the population of the worms.