I wonder if you have time to provide any advice on why my wisteria’s leaves are curling and what I can do about it. I am at a loss. It has been established in its south-facing situation in Maidenhead, Berkshire, for about 20 years and has never had this problem before. I attach a picture of the shrub in its situation and another close up of some typical leaves. All leaves are affected to a greater or lesser extent.
Thanks so much

I seriously doubt it is from high temperatures. Welcome to NGA @MrWisteria.

Two things right off. Have you fertilized it this season or added compost to the soil?

Have you checked the leaves for scale or aphids? Those are both causes of leaf curl.

How often do you water? If you find aphids you can wash them off with a strong spray from the hose.

It is always best to identify a pest and then use the proper means to rid them from your plant/garden.

Hope this is of use. Regards