How to Prune Azaleas…and When!

A few months ago I wrote a post about some of my favorite white spring flowers.  If mine had been in bloom at the time, I would have also included the Mrs. G. G. Gerbing Azalea (Azalea Rhododendron indicum ‘Mrs. G. G. Gerbing’).  Because my G.G.s make up the foundational backbone of my landscape, I love how for a few weeks in April my yard is literally blanketed in white.

Being a Southern Indian hybrid, the larger variety of azalea, G.G.s will grow as big as 8’-10’ tall (and about as wide) at maturity…so they’re the type of azalea that are more likely to need a good pruning every year or so…particularly if they’re planted close to your home or along your walkways. (Note: The smaller variety of evergreen azalea are the Kurume hybrids…smaller and waxier leaves with smaller blooms. Being more compact (growing to 4’-5’ tall) and slower growers, they will likely only need to be pruned every 5 years or so.  The other type of azalea…that you may not even realize is an azalea, is the native azalea.  They are deciduous (lose their leaves every year) and should really never be pruned.)

When to Prune Azaleas

To ensure that your azaleas provide you with their annual burst of color, it’s critical that you prune them at the right time of year, otherwise you’ll be left with just a nice evergreen bush.  The reason for this is that azaleas bloom on “old wood” (vs. “new wood”)…which effectively means that the flowers you have this year were set last year.

So when is the right time of year?  Ideally that would be within 3 weeks of when they finish blooming in the spring. However, if you haven’t pruned yet…don’t fret – the rule of thumb I follow is making sure that I prune before the 4^th of July.  After that you’ll run the risk of cutting off much of next year’s blooms. That’s why I’ll be spending a good deal of time in my yard this weekend!

How to Prune Azaleas

So how do you prune azaleas? The answer to this has a bit to do with your personal preference. Personally, one of the things I like about azaleas is that they aren’t just blobby bushes…naturally they have a more gangly habit.  But if that’s what you want, the how you shear azaleas is easy, you shear them, like you would any other formed hedge. Again, this is not my personal preference – not only does it create a less natural looking formed shrub, but eventually you will only have leaves and flowers on the outer edge of the bush…effectively shading the interior – hence no leaves or flowers inside. If your space or design calls for a more contained or boxed form, I would suggest you choose another shrub (e.g., holly or boxwood).

But if you’re like me and you prefer a more natural looking azalea that has leaves and flowers in the interior, you need to put away your hedge trimmers and pick up your hand pruners.  This will take more time…however, you will achieve the look you’re going for.

So here are some tips for pruning your azaleas:

• • Decide how high and how wide you want your shrub to be and then reach into the interior of your azalea and cut stems at varying heights.
  • I try to make all my cuts at a point where the stem branches…especially for larger stems.  So I’ll pick a stem that is higher or wider than I want it to be and follow it back to where it branches and make a cut there…remembering to vary where I make my cuts up and down.
  • If you make a cut randomly along a stem, you will leave an unsightly stub sticking up…which will likely die and potentially invite disease.
  • After you make a few cuts, step back and see how things look…wanting to make sure you’re keeping the plant’s natural symmetry. Then go in for your next set of cuts.
  • Because it deserves mentioning again, make sure you vary where you make your cuts – up and down.

Additional Information

Although there is much more to certain pruning techniques, I think this is probably enough for most of you to get started.  But for those of you who want to know more, here are some links that you might find helpful:

• • American Rhododendron Society
  • The Daily South – Southern Living
  • Sandy’s Garden

Alright, so there you have it…the when and the how to prune our azaleas.  I hope you’ve found it helpful…giving you a bit more direction for your gardening endeavors this weekend!

Take care,