LEAF SPOTS ON HYDRANGEA
HYDRANGEA MACROPHYLLA WITH DISEASED FOLIAGE On my recent garden visits, I’ve noted an abundance of leaf spots and unsightly foliage on hydrangeas. They can be bacterial leaf spot from an infection by Xanthomonas campestris, or Cercospora which grows from the pathogen Cercospora hydrangeae . I’m also seeing powdery mildew on many plants. You can thank Erysiphe friesii var. friesii (formerly Microsphaera friesii ). If you’ve got blemished foliage, a trip to your local extension office can diagnose which it is so you can apply the proper treatment, if at all.