Lack of light/warmth? Too much rain? Disease? All of it?

What has happened to my penstemons this year? Have 4, one is in flower (sorry don't know varieties but they are not the delicate and fragile kind and are generally robust), the others have lots of leaf but no buds. The tips of the stems look a little scraggy, the leaves curling but I can't see any creepy things. Can anyone suggest what's happened and whether I am likely to be able to fix it? They are in a west facing bed, not that that's made any difference this year! Thank you, Pat W