I have a tall 5.5ft palm tree. All leaves are turning brown, including middle tender leaves. It is near east face window. At night, it gets light from recess lights in room. I water it 3 times a week. I used organic fertilizer (which is meant for herbs which smells bad) while potting. i noticed fungus like thing on the top soil. I am dusting the plant once a month. I love that plant. i don't want to loose it. what am i doing wrong? what is the right fertilizer for palm trees ?