How to prune azaleas – experts explain how to make sure you don't cut off next year's blooms by mistake

Famously described by Gao Xingjian as a perfect example of 'pristine natural beauty', and dubbed the Pinterest star of 2024, there's a reason these oh-so-vibrant blooms are so popular. If you want to keep yours looking its very best year after year, though, you need to learn how to prune azalea.

That's right: while you may already know how to grow azalea, pruning these flowering shrubs is the key to making yours the envy of all who see it. And, considering it's one of those plants that increase property value, we promise that it'll reward you for your efforts.

Better still? That aforementioned effort will only need to be minimal at best; as the Royal Horticultural Society (RHS) points out, these standout shrubs require 'little or no pruning and in fact may be spoilt by harder pruning'.

Sounds like our kind of garden job, quite frankly!

How to prune azalea

While it's important to know how and when to prune rhododendrons, Sean Lade, director of Easy Garden Irrigation, reassures us that 'azaleas don’t require much pruning other than the removal of dead wood and deadheading spent flowers'. 

Sean Lade

Sean holds in-depth expertise in gardening and horticulture, with a focus on designing efficient irrigation systems. His solutions grace gardens and nurseries across the UK, embodying an environmentally-conscious approach to water usage. Sean is always happy to share knowledge, guiding gardeners and growers through regular training on irrigation best practices.

'Prune azaleas after flowering to shape and control size. Be mindful not to cut into old wood, which may impact next year's blooms,' he says. 

'If you need to cut back hard, give the plant acidic feed if soil conditions are poor, mulch and keep well-watered to encourage new growth.'

What you will need

As ever, we always recommend gathering the tools you need for a gardening task before you set to work. 

With that in mind, then, it's important to grab the following before you start pruning azaleas:

• A pair of gardening all-purpose gloves, like these XGATML Clip Gloves from Amazon
• A pair of bypass pruners, like the Okatsune 103 Bypass Secateurs from Amazon
• A pair of bypass loppers, like the Spear & Jackson Razorsharp Telescopic Ratchet Lopper from Homebase
• A bag for your clippings (which will, incidentally, be perfect for your compost bin)
• A good quality fertiliser, such as Miracle Gro Premium Azalea, Camellia and Rhododendron Continuous Release Plant Food
  

Step-by-step guide

Before we tell you how to prune azaleas, it's important to make sure you tackle the job at the right time.

'Pruning azaleas is best done after they bloom, usually in late spring or early summer,' explains Andrew O'Donoghue, one of the directors of Gardens Revived.

Andrew O'Donoghue

RHS-trained gardener Andrew O'Donoghue set up Gardens Revived with his brother, Christopher, in 2018  to create a thriving family business. Together, they have worked on residential gardens, listed buildings and gardens, flower shows and large estates with some exceeding 70 acres – many with historical significance.

1. Tackle the problem areas

As mentioned already, azaleas don't need to be subjected to a routine pruning like so many other plants – instead, Andrew says you should focus on 'removing  diseased, damaged, congested or crossing shoots'.

'This helps improve the overall health of the plant,' he explains.

2. Shape the shrub

A big part of pruning azaleas is about maintaining their shape and size (there's a reason, after all, that they are counted among the best trees for small gardens or balconies).

'Trim back any overgrown branches to maintain a neat appearance,' says Andrew, 'and whip out any that are growing in unwanted directions, too.'

3. Boost growth

Taking care to step back and assess the azalea's overall appearance, Andrew says you can also take some time to encourage new growth (and more blooms) by selectively pruning back some of the older branches. 

'Cut them back to just above a set of healthy leaves or a joint,' he advises, 'and, if your azalea is densely packed with branches, thin out some of the interior branches to improve air circulation and sunlight penetration.'

4. Mulch and feed

Once you've finished pruning your azaleas, it's important to give them a good mulching with well-rotted material, as well as a dose of good quality fertiliser, too.

Be sure to follow the instructions on the packet carefully.

FAQs

When should azaleas be pruned?

Much like lilac, the best time to prune is at the end of your azalea's bloom cycle (depending on the variety, these shrubs usually flower between March and June).

How do you deadhead azaleas?

Deadheading is very different to pruning azaleas, but it's just as important; all you have to do is take a pair of secateurs and use them to carefully snip off any brown, faded flowers from the plant. 

Now that you know how to prune azaleas, you can sit back and enjoy the fabulous floral display with your feet up. You won't need to lift a finger until it's done.

Just be sure to 'always use clean, sharp pruning shears to make clean cuts and reduce the risk of disease transmission,' warns Andrew.