I recently moved from a town house to an apartment. Since I've been here my palm trees( 3 in one big pot about a foot and a half to two feet high) have white fuzzy looks like mildew at the base where the leaves meet the trunk and also on the actual leaves. There are no bugs seen to the naked eye, the plant is still growing new leaves but lower ones are browning and I pull them off. What is this stuff and how can I make my plants healthy again??