My otherwise healthy young wisteria has yellow spots on lower, older leaves which is spreading. Is it root rot or something else? Looks like fungus. How should I treat it, please? Thanks so much.
Yellow Spots on Wisteria Leaves
Certified GKH Gardening Expert
There can be a few reasons for the yellowing leaves. Watering issues; to much or to little.
Insects or fungus and even nutrient issues.
I do see mottling in the coloring of the leaves which does appear to be Tobacco Leaf Mosaic Virus.
You can try applications of a fungicide.
Here are some links with more information.