Blind fuchsias

I have a dozen or so hardy fuchsias in my garden. Some of them are flowering
fine, but a few are coming blind and the new leaves are small and twisted. I
see no sign of beasties or rust. I have now sprayed with insecticide and I
kept them moist during the dry spell.
Anyone recognise the symptoms?
--
Jim S
Tyneside UK
http://www.jimscott.co.uk
.