Once the flowers have faded is the perfect time to prune those old azaleas that have been needing some serious pruning attention for years. Chances are you have some of them, so keep on reading.
Your azaleas need pruning if they're underperforming in the blooming department, thick and crowded, too large for where they're growing, or badly shaped due to damage or other things that just happen to them. Young azaleas can go for years without needing to be pruned, except for maybe a bit of thinning.
What's called renewal pruning is the place to start. The goal is to remove 1/2 to 1/3 of all the stems, and your first choice for removal are the dead, the dying and broken stems. Next, those that are lying on the ground, making it hard for you to see weeds, especially the vines that can devour shrubs so quickly. And the branches that start at the outside of the plant and grow toward the center should be removed, since they cause crowding. And be sure to remove at least one of the oldest stems, maybe two. You can tell the oldest by their thickness and coloration.
Cut the stems down where they start or as close to the ground as possible. That'll produce new growth from the base of the plant and a nicely shaped plant. And always cut 1/4 to 1/2 inch away from the next lower branch, so as not to leave a stump.
Then if a shrub is also too large - in height or width or both - you can make "head cuts" to shorten the remaining branches. Head cuts remove a foot or more from the ends of the too-long stems. Reach in and cut at slightly different heights and closer in than where you'd like the plant to stop; that way you end up with a natural shape that doesn't have to be sheered regularly.
Bottom line, you're removing a shocking amount of plant! Branches and branches pile up and first-time pruners become alarmed, but relax. Over the next few months you'll see how well your azaleas respond to this type of tough love and you'll become a believer. Maybe even an avid pruner - people love it once they see the results!
Here's more good advice about pruning azaleas.
Now just imagine being the gardeners in charge of pruning this azalea maze at the Getty Museum.