White fuzz on Himalayan sweet Box

Asked September 11, 2019, 11:06 AM EDT

Attached are pictures of the white fuzz on my one sweet box. I’m guessing it’s powdery mildew, but I’m new to sweet box so I thought I’d check with you to see 1) what it is and 2) what remedy we should take It’s in mostly shade, seems to get good air circulation and was planted a year ago. The other sweet box in the bed look fine, as does this one except for the fuzz. Thanks for your help

Montgomery County Maryland shrubs pest insects and mites

1 Response

Hi -- It looks like your sweet box plants have an infestation of mealybugs. You can treat them by applying insecticidal soap or horticultural oil. You will have to get coverage for effective treatment. Read and follow the product label instructions for application rates and timing. http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advi...

We also recommend managing the ants. The ants actually "tend" the mealybugs. They fend off predators to keep the mealybugs alive so that they will continue producing the honeydew that the ants eat. We recommend using outdoor ant bait traps around your plants in this situation to help control the ants.

Christa