You can prune them almost severely. The problem with doing that now, is the risk of sunburn to bare stems.

If you want to prune most of the leaves off, the flowers must be sacrificed by pruning in early spring.

Otherwise, keep enough leaves to shade the inner stems.

I renovated a 'Purple Splendor' azalea hedge at the Oregon Health Sciences University, years ago, removing up to 75% of the canopy in March.

By autumn, there was a filled-in and smaller hedge. Looked great the next year - loaded with blossoms.

Thanks for that. Right now there are a few small leaves and the stems are bare so I don't think sunburn will be a problem. It is in an area where it is shaded from the worst of the sun. The resident bambis have been having a go at it so I think I should prune now. Deer fence is looking promising.

I prune my deciduous azaleas as soon as they finish blooming, lightly to shape or drastically to shorten. They respond well to both types of pruning.

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