I have a Wisteria of the blue variety which is seven years old approx having spent two years in a pot and the last five years in a permanent position in my suburban garden in north west England. It is positioned in the garden where it receives the morning sun at approx 10:00, some parts not until about 11:30.
For the last two years it has begun the process of blooming where a massive bud crop grew to between 3” and 4” in length and then stopped. The individual petals of each bloom would then fall off when touched. The result was that the plant did not bloom. Now well into the blooming season one or two blooms have grown to full size and are attempting, unsuccessfully to bloom. The leaves are now on the vine and otherwise the plant looks very healthy.
I did think that perhaps the buds were being killed by the sun on a chilled bud as a result of a late spring frost however, this year we did not have a late frost to affect the buds. Has any one had the same experience and if so how did they remedy the problem.