My carbboard palm tree, which is planted in the yard in Tampa, FL seems to be drying up.... underneath the leaves, it has like a white mildew all over them. Can any one recommend what to do? I am a "newbie" in taking care of cardboard palm trees.. We have had this plant for around 12-15 years and never had problems... until now.... any help would be appreciated.... if you can, please be as specific as possible with suggestions. TKS!

I will try to add image later.