11 year old abelias in full sun, too large, do not bloom till late summer, and then not heavily. These were supposedly Little Richard Abelia put in by a landscaper. Should I cut them way back next winter?
Pruning is best done in the winter when the plants are dormant.
Since yours are well established it may be a good idea to go ahead and remove some of the old growth. This should help get the shrubs in better shape and should encourage flowering.
Do not remove more then 1/3 of the plant at any prune.
You can also fertilizer with an Azalea fertilizer, twice a year-late February and early June is a good time to fertilize.