Texas A&M AgriLife Extension Service

 

As a horticulturist, it might surprise some that I had never even seen an azalea before moving to Tyler. I had spent all of my life in Central Texas and the Panhandle, and a patch of acidic soil is virtually unheard of out there.

This might be the Rose Capital, but I have seen just as many or more azaleas! So, needless to say, I have been playing catch-up on azaleas, and I learn new things about them every day.

A few days ago, a fellow gardener brought in a pot of what appeared at first glance to be some kind of mushrooms. He said they were on his azalea and wanted to know what they were. Upon closer inspection, I could see they were large growths on the leaves and even stems of his azalea. After doing a little digging, we determined he had azalea gall, a fungal disease that causes distorted leaves and buds from April to May. The fungus of interest here is Exobasidium vaccinia, a fungus that also affects members of the Vaccinium genus, including cranberries, blueberries and huckleberries to name a few.

In late spring and early summer, the infected plant tissues swell and develop a white coating that produces fungal spores, which will later be released from the plant, drifting around and infecting neighboring plants. Infected plants show no symptoms until the following spring. Cool wet weather facilitates new infections, so I wouldn’t be surprised to see more azalea gall this time next year with the recent rain.

Fortunately, infections are relatively straightforward to treat and manage. To control the spread of azalea gall, remove by hand the infected swollen tissues before they turn white to prevent the galls from producing new spores and infecting other plants. If you have symptoms of azalea gall, it’s too late to use a fungicide, but fungicide can be applied as a preventative measure. Begin treating with fungicide just before the flower buds open and at 10-day intervals until flowering ceases. For small plantings, hand removal is recommended.

Don’t forget, the Smith County Master Gardeners have their annual home garden tour from 9 a.m. to 3 p.m. May 28. Advance tickets cost $10, and day-of tickets will be $12, cash or check only. For more information, call the Smith County Extension office at 903-590-2980. Mark your calendars!

 

Kyle Tengler is the Smith County horticulturist with the Texas A&M AgriLife Extension Service.