I have wisteria leaf mottling with no flowering but dense growth. For 2 years now nothing but yellow and green mottled leaves. Is this treatable? And HOW?
Wisteria Leaf Mottling
Certified GKH Gardening Expert
Most likely it is a combination of over fertilization and mildew on the leaves. Dense growth can mean the plant is getting too much nitrogen, which then weakens the plant as well as making air circulation difficult. Both of these issues leave the plant open to powdery mildew, which on a wisteria looks like yellowing and mottled leaves.
I would recommend pruning the plant well to thin it out and open up the air circulation. And treat it for powdery mildew as well. If you are fertilizing the plant or plants near the wisteria (like the lawn), stop fertilizing close to the plant.
This article will help: