How to Prune Azaleas

There’s no doubt about it — azaleas are a much-loved flowering element in residential landscaping. The easy-to-grow, colorful shrubs are celebrated in festivals and spring garden tours across the U.S., especially in the South and Southeast where they’re abundant. If you love the vibrant colors of azaleas, you can probably grow them in your yard because they are not overly fussy.

Azaleas do well in USDA Plant Hardiness Zones 5 through 8, meaning they can thrive in all but the most extreme hot and sunny climates. When in bloom, azaleas produce vibrant shades of white, pink, purple, red, orange and yellow. They usually bloom from mid-April to May, and are a sure sign that spring has arrived.

Most azaleas in North America are deciduous, meaning they drop their leaves in the fall. Exceptions are Encore azaleas, an evergreen azalea-rhododendron hybrid that blooms from spring through fall and can thrive in slightly hotter climates. According to the Azalea Society of America (ASA), depending on conditions, azaleas will grow between two and 10 inches per season. If kept free of pests or diseases, they can live for decades. Some specimens in Japan are hundreds of years old!

To keep your azaleas looking their best, use these tips on how to prune azaleas.

Why Prune Azaleas

Deanna Curtis, senior curator of woody plants for the New York Botanical Garden, told us nothing bad happens if you don’t prune your azaleas. They’ll just grow larger. “They are not a shrub that requires much pruning at all,” she says, “though they are frequently pruned to reduce or maintain their size.”

And like most shrubs, some regular pruning can keep your plants looking neat and well-cared for. For larger specimens, pruning helps keep the branches from spreading too much and creating a hollow look in the middle of the plant. “The only azalea pruning that is critical is the removal of any dead, dying or damaged branches,” says Curtis. “All other pruning is just personal preference.”

When to Prune Azaleas

The ASA says it’s best to prune azaleas in the early spring before new buds form. This gives the plant a full season to fill out and grow new wood. Curtis says to also prune right after the blooms have faded, to get the best flower display for the following season. She adds that you should remove dead, dying or damaged branches at any time of the year.

How to Prune Azaleas

Start with the right equipment. “If you want to shape them in any way or reduce their size,” says Curtis, “the best tool to use is a pair of hand pruners.” Make sure they’re sharp, and sanitize them with rubbing alcohol before you start clipping spent blooms and dead or damaged branches.

Unlike shrubs that can be cut way back each year, Curtis says azaleas should be cut back a few branches at a time.

“To fully rejuvenate older azaleas, cut one or two large branches back to between six inches or a foot from the ground per year.” she says. “As the new growth develops from the base, keep removing the larger, older stems annually until they are all reduced.” Otherwise, she says, you can keep their natural growth habit by cutting back upper individual stems with hand pruners.

Pro tip: Even if your azaleas function as a hedge, they should not be shaped with hedge clippers or cut into a neat hedge shape. “They rarely look good pruned this way,” says Curtis. “They are often pruned at the wrong time, resulting in a smattering of flowers the following year across the hedge.”