Pruning Rhododendron?

I have two old Rhododendrons in the garden that have become very leggy and frankly looked a real mess when they flowered this year with the stems bent down unable to carry the weight.

Is it possible to cut them back hard or should I just dig them out and start afresh?

 

You can usually hack away at them, they are tough as old boots and really spring back from the base. Do it soon so they have time to regrow before the winter. I have never had a problem with radical pruning on a rhody but I do know that a few cultivars and species are sometimes grafted (R. yakushimanum for example) ie not grown on their own roots, and I would guess you might want to be more careful with them, as they might sprout from below the union, and the rootstock take over. Yours most probably are not of this kind, but do check!