In the South, gardens just wouldn’t be complete without the welcoming spring blooms of azalea. However, the Southern fantasy ends as soon as strange growths appear on the leaves and flowers of your prized bloomer. It’s a bit unnerving, to say the least, to see leaves looking like they’ve undergone the invasion of the plant snatchers!

Azelea leaf gall

The swollen leaves on this infected azalea almost look like marshmallows.

Photo Credit: R. Kenneth Horst

Exobasidium vaccinii

Exobasidium vaccinii can make azaleas take on a whole new look.

Photo Credit: NCSU Plant Pathology Image Archive

Azelea leaf gall lesions

Symptoms start out with a few small lesions before beginning to swell.

Photo Credit: NCSU Plant Pathology Image Archive

Popcorn galls

Galls can be large – or as small as a piece of popcorn.

Photo Credit: NCSU Plant Pathology Image Archive

Of course, little green men aren’t to blame. But there is a fungal culprit for this azalea malformation. Exobasidium vaccinii, otherwise known as azalea leaf and flower gall, causes azalea leaves to look thick, fleshy and curled. The fungus also makes crazy-looking growths appear on flowers and foliage alike.

As a Cooperative Extension agent, I saw a lot of home gardeners’ clippings of “alien azaleas,” along with requests on how to fix the problem. These gardeners were often pleased to hear that simply by cutting off the funky growth, they’d likely solve their plant’s gall woes. Pruning out infected branches into healthy tissue removes both the fungus and the symptoms the disease causes the plant to exhibit. The important thing is to discard the infected branches so that spores can’t reach the plant again. Also, be sure to disinfect your pruners with a rubbing alcohol or light chlorine solution between cuts so you don’t spread the infection to other parts of the plant – or to other plants in your garden.

Thankfully, gall problems usually aren’t an annual headache, and symptoms are most often sparsely distributed on a plant. Whether or not your plants ever even get leaf gall depends on good ol’ Mother Nature: Cool, wet weather in late spring and early summer encourages the spread of the fungal spores. The trick is as soon as you notice galls on your azaleas, remove them early, before a white spore layer appears. This way, healthy tissue will be protected from infection and less likely to produce galls the following year.

Fortunately, azalea leaf and flower gall is more bark than bite. So the next time you visit your azaleas and discover they’ve been “puffed up,” there’s no need to fear – as long as your pruners are near!