In article ,
says...

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.




--
nahgoe

I would be hugely surprised if you haven't had a late frost, Saturday
night was our most recent, Cold windy weather can also cause the
individual flowers to drop, but another reason is dry roots, Wisteria are
swamp plants in the wild and will take offense if dry at the wrong time
--
Charlie Pridham, Gardening in Cornwall
www.roselandhouse.co.uk
Holders of national collections of Clematis viticella cultivars and
Lapageria rosea