Got azaleas? Of course you do! (It's for good reason that some call our region the "Azalea Belt.") And are your azaleas the size or shape that you want them to be? All of them? Probably not. And soon after their blooms fade is the best time to remedy that situation and avoid pruning away next year's blooms. Buds for next year's blooms will start forming in mid-summer, so you have until roughly the end of June to prune your azaleas without danger of de-budding them.
Azalea maze at the Getty Museum Garden - not for the home gardener!
To Correct Misshapen Azaleas
Renewal or renovation pruning is the technique that brings old shrubs (not just azaleas but also viburnums, forsythias, mock oranges, spireas, and cherry laurels, among others) back to the attractive and healthy form they were in when you bought it - over time. That disclaimer about time is because we gardeners can only remove limbs and encourage new growth and then wait; we can't make it all happen at once.
If your azaleas are old, overgrown or badly misshapen, here's what to do this year and the next two years: Simply remove one third of all the stems down to their origin (close to the ground). This is counter-intuitive to most of us because really, who’d ever imagine doing it? But honestly, I've done this to dozens of old shrubs over the years and and seen it work wonders. It stimulates the plant's own growth hormones exactly where we want new growth to happen - at the base of the plant, rather than at the perimeter. Sadly, we see too many examples of azaleas and other multi-stemmed shrubs being pruned (or worse - sheared) at the ends of the branches, which only makes more new growth happen at the perimeter of the shrub, where there's already too much growth.
The following spring, the shrubs should have produced lots of new growth at the base. Just reduce the number of shoots per stump to two or three, leaving only the strongest and best placed ones.
Full, right-sized azaleas
Azaleas Too Large?
Of course the best policy is to choose plants whose ultimate size is exactly right for the spot they're growing in, but mistakes are made, and selecting the wrong size shrubs is a common one. Besides mistakes in plant choices, sometimes we make changes in our gardens that make down-sizing of certain plants a great ideas. Whatever! Some plants that are too large for their site are hopeless cases because they can't be pruned back to the correct size - especially many conifers but with azaleas there's usually an available fix - the renewal pruning described above, which reduces the size of the plant. For the purpose of keeping the shrub smaller, this renewal pruning will probably need to be performed every year, indefinitely.
Regular Pruning is Minimal
All that said, azaleas look best when minimally pruned, allowing them to retain their naturally graceful form. Here's what they need to maintain their good health and beauty.
- Removing all dead, dying and diseases branches and stems – back to where they start. (Never cut just anywhere, leaving a stump. Cut a half inch above a branch.) This can be done any time.
- Every year or two, removing at least one of the oldest stems back to the ground or close to it. This is often the tallest of the stems, and almost always the thickest and showing age in color – usually grayer.
- Often, azaleas look best in borders when they've been limbed-up. That means removing the low-lying limbs, especially ones lying on the ground or on top of groundcovers. Too much limbing up can ruin the natural shape of the plant, so keep a light touch.
- Finally, removing or shortening branches that crowd out other plants that aren't as amenable to pruning (especially conifers, whose shapes are so easily destroyed by pruning). Same goes for branches growing over sidewalks and paths.
Azaleas carefully pruned to keep the path clear
Tools for Pruning Azaleas
Hand pruner and loppers should easily do the job; I've never had to resort to my pruning saw for an azalea. Just remember that if you're using your favorite hand pruner (mine is the #2 Felco) and straining to make the cut, the branch is too large for hand pruners and it's time to step up to the lopper. Never mind that the hand pruner MAY cut that branch if you use enough muscle; hand pruners can be irreparably damaged by doing that.