Bacterial Leaf Spot:Xanthomonas Compestris pv. Hederae- many plants are susceptible to bacterial diseases, especially when the weather gets hot and humid or during gloomy winter months. Plants can begin to show sign, such as wilting or leaf spot. Bacteria are almost always present on plant surfaces and only cause problems when the conditions are just right, including high humidity, crowded plants, poor drainage or air circulation or proper irrigation is key to helping control any bacteria on plants. This condition is most active under hot humid conditions. Common symptoms are leaf yellowing beginning at the leaf tip-leaf margins. They may turn reddish brown instead of yellow during hot conditions, early signs of infection are small spots that turn yellow. The center will then turn brown as it worsens, the leaves will turn yellow and fall. In some cases, on different plants, leaf spots turn green, with reddish margin, mature spots turn brown or black, leaf stems begin to turn black and shrivel.
