Rule of thumb is to trim no more than one third of the plant. However sometimes a 'rejuvenating' pruning can be necessary. If the shrub is totally a wreck, you can prune an Azalea down as far as 6-12" on the main branches, removing any dead or undesirable branches.
Spot-on advice from Four Seasons. Make sure you prune before July 1 so you don't affect the next year's blooms.
I recommend the renovating pruning that Four Season Nursery suggests. You will be amazed. Make sure to water and mulch after pruning, keep the plants happy.
Thanks for the input. Now all I have to do is wait until the azaleas bloom before cutting back.
I have discovered a leggy looking azalea on the south side of my future home... by the time we move in, it will be October so I am wondering when should I prune then?
@Marlena I would wait until they bloom in the spring.
Ok, Thank you Doug!
Yes, what Doug said. Pruning in the fall usually results in new growth that going into winter will freeze and die. Right after blooming is the best time to prune a spring blooming shrub. Later bloomers can be pruned late winter during dormancy.
Our dumb neighbor was looking for the property line and cut down to the ground several of our beautiful azalea bushes. It took about 3 years but they are as beautiful now as they ever were and not quite as wild looking. A good hard trim every once in a while is a good thing for them. Just be sure to trim them after blooming.
Thank you all!