Posted: 23/01/2013 at 13:34
If they didnt get enough water the previous early Autumn then they can be shy to flower. You can usually start to see the signs of new flower buds by about October IME.
They are in pots, so that will have been down to you despite all the rain last year. If that deck is in sun then they will have been dry at their roots & that wont have helped. They are basically woodland understorey plants, so actually prefer a part shade position.
I'd feed this spring, keep watered, with rainwater if your tap water is hard, & add some more ericaceous compost as a mulch to the pot. If necessary/possible move the pots out of sun into a cooler spot.
They may still not flower this yr, but next yr, if watered in autumn should do so. J.