Wonder what causes lichens and white-out bark on Crape Myrtle Natchez? The usually cinnamon-brown trunk became whitish-cinnamon-brown since I planted it last year in July and watered a lot to make sure survival the hot weather planting. Will the bark brown again?

Regarding lichens, I bought these trees as I was told that lichens do not grow on Crape Myrtle Natchez, particularly 'Natchez', but the upper branches of all of them have a lot of leafy lichens.