I know nothing about palms

[Fatcord]

I have been reading on palms because I know nothing about them. I never had a customer with them until now. Looks like windmill palms. Well my customer said he and his wife were sitting on the patio and noticed a black mold on the tree. I have no idea if it is on the fronds, at the base or stem. I will find out tomorrow. They probably have been drinking too much. I was just over there last week and noticed nothing. If there is a black fungus on palms what would could it be and treatment? Thanks input appreciated!

 

[sac-climber]

There is a fungal disease called Diamond Scale its seen mostly on Washingtonia. I've see it mostly in areas with excess moisture in the air. If it's possible to change the environment that is your best fix. Possibly use a horticultural oil mixed to the proper ratio and apply till runoff.

PS... I just read Trachycarpus is resistant. Is that the species for sure?