Supposedly August is the cut off date. Any pruning should be done between after the time the azaleas bloom and August to have a bloom the following spring. I cut back some of mine, the tops were badly damaged in the freeze, but they were blooming at the bottom. I was planning on cutting them back after the bloom, so I did it now so I could at least see the little bloom I had. BTW, azaleas usually go through a 'molting' period of leaves after blooming and look like hell. That plus the freeze we had are making all azaleas look pretty bad this year. They should start to put on new leaves in a few weeks.

Just get rid of the azaleas.....given the choice :-)) Even being cut back routinely, they will regrow and want to take over again. If you are careful, you should be able to remove the root system once they are cut back but that is not a requirement. Typically, laceleaf JM's are not underplanted with anything other than groundcovers as their weeping habit typically produces branches to the soil level. If a high graft tree or if trained to be more upward in growth habit, you could try underplanting with something like epimediums, which will never grow too high nor need division.

If your azaleas are healthy you will be able to prune back drastically, but you won't get a nice flower display for a few years while it's readjusting to the dimensions you want it to inhabit. Most shrubs won't do this, but you can sometimes cut an azlea back almost to ground level and still have it rejuvenate, although it takes a few years to do it. You should cut it back immediately after flowering finishes, or as soon thereafter as possible. This would probably be an acceptable weekend to do it. You may have to fertilize afterwards with an organic fertilizer and make sure the shrub stays appropriately watered if you get no rain. It will look pitiful at first, but you should get new growth back before the end of August (or September at the latest). Next year you can being lightly shaping that year's new growth.

not a great pic.. but the whole top looks dead... cut it down ... the only question is ... was it a grafted cultivar... and what you might have growing from the bottom, if it was ... be nice to know where you are ... to discuss whether it is zone appropriate... if 2 winters in a row knocked it back ... there is also the issue if it was a recent large transplant ... there is never any real reason.. to leave a dead.. or mostly dead piece of wood there... take the dead part down.. and it will improve the look of the rest of it.. 100% ... ken