My wisteria is flowering but has no leaves at all. What should I do?

Be glad! Everyone usually has the opposite problem. You can feed it with something high nitrogen, like Growmore or similar - nitrogen produces leaves in particular, not so good for flowers. And water.

I think thats the way it should be, Apparently its all in the pruning. We were a bit slap dash earlier this year so now our wisteria has flowered well but at the same time slightly obscured by leaves appearing too early. I assume you pruned it? Must have done a good job. The leaves will come don't worry.