Standard Wisteria not fully flowering

I have two mature Wisterias which I prune carefully at the right times each year. One is a climbing one which has done very well this year and is currently in full flower.

The second one is more of a standard which has overgrown the fence that it was trained up against. As with the other one this has started off with the most promising abundance of racemes, nearly all of which have started to flower... but that was over a week ago and they've not fully bloomed at all. The buds have started to bloom but seem to have ground to a halt, blooming no further. The same thing happened last year, the only difference was that there were fewer racemes.

Are there any Wisteria experts out there who can point me in the right direction towards finding out what is holding this wisteria back please ?

 

I think it could be down to the very dry weather. Or a lack of Potash in that part of the garden. Get a cheap bottle of tomato fertiliser from Wilkos and give a weekly feed . If it doesn`t work for this year, it should improve next years flowering.

 

I'm agreeing with the dry roots theory.

My other thought is frost, could the flowers have got slightly frosted.
I've seen where half the flower comes out and the rest of the flower buds on a stem are dead due to partial frosting.

 

Hi Pete
You are one step ahead of me tonight ,, I think we have had a couple of cold nights and very hot days , when growing on the wall it very rarely a problem as the heat off the wall over night just keeps the cold off but when grown in the open , you end up with half a flower or looking like dried hops

Spruce

 

I don't pretend to be any sort of expert on wisteria, so I can only go on what those in my garden do.

I know there is a right and wrong way to prune them and that they should be pruned twice a year, however .... one of mine has never been pruned in it's 19 years of life, except to keep it in some rough sort of shape and it is always thickly covered in bloom (just coming into its own now). I don't think I've ever fed or watered it and it 'takes its chances' on a windy corner facing north.

The other two are against fences (one facing east, the other facing west). Both of these are only about 6 years old and always flower a bit later than the original, in fact the buds are only just beginning to fatten and open and they too have come to a sort of halt. This I've put down to their location ... whereas the north facing older plant gets some sun (a little one side during part of the morning and little on the other side during part of the afternoon), the younger plants have had either the full glare - and heat - of the recent morning or afternoon sun, but not both and I'm thinking that since they're probably not used to the sort of heat they've been subjected to recently, they've just got a bit stressed and are taking a 'breather'.

As I say, not exactly an expert answer, but a 'best guess' which may be of some use.