Wisteria buds all formed and beginning to lengthen but are drying up and falling off before blooming. Is there a problem I can rectify?
Certified GKH Gardening Expert
It is likely caused by thrips. Some varieties of thrips attack the base of flower buds and cause them to dry up and fall off before they open.
A less likely cause may be a fungus.
Treat the plant with both a pesticide and a fungicide. This article will have more information about thrips: