Answer: Wait until after flowering finishes and then you can prune your azaleas. Once the flowers fade, new stems and leaves are produced. If they are very much different in size, it may take 2-3 years to make them uniform because you won't want to prune off more than about one-third of the plant in any one pruning session. Wherever you prune, expect one or two new branches to develop. If a single stem (or two) grows much too long during the summer months you can safely prune it back, but save major pruning for late spring after the flowers fade.
Best wishes with your azaleas.
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