By Amateurdavid
United Kingdom 
why did my azaelias die last year they came into bud as normal but flowers failed to open buds then dropped off followed by the leaves they were growing in large pots
9 Mar, 2012
Answers
Where are you in the UK and did you protect the pots from frost the winter of 2010 - 11? Alternatively as Ojibway points out they may have been affected by the drought.
9 Mar, 2012
Too cold ... they frosted and dropped off. Azalea, like camellia and rhododendrum, in anything other than a good protected spot from large extremes of temperature just as they are budding will always drop buds. If they were not watered last year, as suggested above, or fed appropriately, then they will not have put on strong growth to produce and maintain buds.
10 Mar, 2012
Seems that they may have suffered a shock, through drought or frost?
9 Mar, 2012