How do I rid my crepe myrtles of this fungus?

It almost looks like lichen, but I'm not sure. Another possibility is Bark Scale. Check with a local nursery. In the meantime, here's a link that may help:

https://www.gardeningknowhow.com/ornamental/trees/crepe-myrtle/crepe-myrtle-bark-scale.htm

It does look like bark scale.

https://thegoodearthgarden.com/control-crapemyrtle-bark-scale/

https://www.google.com/search?q=Crepe+Myrtle+Bark+Scale&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiun47P2oT3AhVlj2oFHajDCK8Q_AUoAnoECAEQBA&biw=1536&bih=723&dpr=1.25

Contact your cooperative extension, they are very helpful.

If you are suspecting lichens, take a look here for help:

https://homesteady.com/12003640/what-to-use-for-lichen-on-crape-myrtle

Hi Lyn, from the photo it looks like lichen. Do you have a close-up you could share? Bark scale is white or gray, waxy, and looks like miniature cotton wool rolls while lichen is more crusty and green-grey in color. Here's a good article on how to treat crape myrtle diseases that will hopefully help - https://hgic.clemson.edu/factsheet/crape-myrtle-diseases-insect-pests/

Thank you everybody, going to go have a cleaning session lol

This is a plant-like organism called lichens. Lichens are self-sustaining organisms that attach and grow on the bark of trees and shrubs. They are not parasites and they do not kill the branches or plants they are growing on. Just seeing lichens is not necessarily a sign of trouble if plants otherwise are doing well.

However, prolific lichen growth is often a sign of plants in decline. Shrubs and trees that are in low vigor and are unthrifty have thin leafy canopies that allow lots of light to shine on the branches. It is this abundant light that causes the lichens to grow abundantly. Abundant rainfall also encourages lichen growth.

The best you can do in these cases is to fertilize the plants.

Dan Gill

Consumer Horticulture Specialist

This resource may help you out https://www.southernliving.com/garden/grumpy-gardener/whats-wrong-with-my-crepe-myrtle#:~:text=Control%3A%20On%20small%20plants%2C%20wipe,control%20insects%20that%20secrete%20honeydew.

Although not necessary, sooty mold can be washed from the leaves and bark by spraying foliage with a dish soap solution (4 ounces per gallon of water), waiting three to four minutes, and then rinsing the foliage with a strong stream of water

Hi Lyn: I had this on my tree. I used a spray bottle with some warm water, maybe a gallon, a 1/4 cup of dawn and 2 Tablespoons of bleach. I sprayed the areas and the next day I used a broom to wipe most of it off. It didn't come back.

It is lichen, The growths cause little or no harm. They obtain needed nutrients and water from the air -- thus the name air plants. With crape myrtles, the life of lichens and moss is often short-lived as these trees and shrubs shed their bark to cleanse the surface.

Hi Lyn, it looks like lichen, it's harmless to your trees,

https://www.youtube.com/watch?v=K9-nm7hVCig

Hey everybody.. the stuff on my bark is more flat, not curly like the one in the video. Maybe bark scale. I washed the trunk of both trees will check back in after Monday. Gonna let the dish soap brew on it a bit then I will give it a bit of a soft scrub and rinse, fingers crossed.

Here is the same crepe myrtle tree. I used 2 teaspoon of dish soap and about 1/4 cup or less of bleach in a gallon of water. Poured it over the trunk and let it sit over night. Used a nylon bristle brush but it wasn't doing great so my hubs got out the power washer on low and it worked great. After image posted above. Looks like this one is small. 😒

here are some tips for ya https://homesteady.com/12003640/what-to-use-for-lichen-on-crape-myrtle