Q.Wisteria Disease
My wisteria has brown through to cream patches on its branches and has a lot of dead branches. Is this a virus? Or could it be dry and need watering?

Certified GKH Gardening Expert
The patches sound like lichen, which does not kill plants but often attaches to sick plants. I would suspect that a fungus is attacking the plant. Treat the wisteria with a fungicide. I like neem oil myself as it will also kill any pests on the plant. Here is more information on it:
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm