Diagnosing Wisteria Leaf Wither: Mildew, Mites, Sun, or Water

Judy in Nashville had two first-year blooming wisterias. One withered; the other looked fine. Lots of rain, mild temps, no visible bugs.

Four Possible Causes

1. Powdery mildew: Brown leaves, maybe fuzzy white patches. Treat with copper fungicide (spray both leaf sides). Safe for pets/people.
2. Spider mites: Hard to see; foliage looks "singed." Check leaf undersides with magnifier. Control: Neem oil or ladybugs. Frost kills them.
3. Sun exposure: Is the affected plant getting more reflected heat (e.g., off a light-colored wall)?
4. Delayed drought stress: Inconsistent watering earlier summer can show symptoms 4–6 weeks later.

Send photos if needed.