I have a very old wisteria, perhaps 150 years. It is growing outside my conservatory and the trunk comes through a very large hole left in the wall. It has been very prolific flowerer until this year. We have very few blooms and the leaves are looking very unwell and slightly yellow. I have become aware of wood lice in the very old trunk. Is this the problem? How do I fix it?
Certified GKH Gardening Expert
Wood lice typically feed on decaying material, so they are likely more a symptom of the problem, rather than the cause. The fact of the matter is that the plant may be just dying from old age. Plants, like animals, have a life span and your wisteria is certainly at a venerable age. But, you should try to do everything you can to save it. Ideally, you should have a horticulturalist take a look at it. At a basic level, treat the plant with a pesticide and a fungicide (neem oil is organic and is both a pesticide & fungicide). Plus, make sure it is getting the water and fertilizer it needs.