English Laurel white mold
One of my five English Laurels has a white powdery mold on its trunk. It is suffering, not as robust as the other four. All planted two years ago. No sign of the mold on the others. The mold is not on the leaves. I’m in Takoma Park, MD.
Your laurel probably has prunicola scale, which is fairly common on laurels. (You can send us a photo attached to a reply for a definitive id.)
Prunicola scale is an insect which protects itself with a hard covering like a turtle shell when it is mature. When immature (crawlers) it is easier to kill.
Here is information on this category of scales, known as "hard" scales: https://extension.umd.edu/hgic/topics/armored-hard-scale-trees-and-shrubs
Besides the management options given, you can scrub concentrations of scale on a trunk with a stiff bristled brush (not metal). This will kill some and expose others. Then immediately spray them with the pesticides on our webpage.
Thank you, Ellen. So you can confirm I am attaching a photo of the whole shrub as well as a tight shot of the trunk where the largest concentration is. Again, nothing is on the leaves, just the bark. Thank you!
Yes, that is the sucking insect called scale.