Indoor palm trees bring a feeling of tropical paradise into your home. However, these plants can be a little temperamental, and they tend to pick up many of the same diseases that other houseplants do. The best way to keep your tree healthy is to know the signs and symptoms of indoor palm tree diseases, so that you can treat potential problems quickly.
Spider mite infestations cause small, red and black spots on the leaves of your palm. These mites also weave small webs in between the fronds of the palm and toward the base of the leaves next to the stems. Use gloved hands to remove the webbing from your palm, then spray the plant with a mixture of mild, green dish soap and warm water to kill the mites. You can treat your plant with this mixture daily until the infestation disappears completely and the plant shows no signs of spots or webbing.
If your indoor palm's leaves have a rough texture and spots that are brown or black and swell and rupture over time, then your palm has false smut disease. Use sterile pruning to remove affected foliage and control the problem. If this does not eradicate the disease, then you can apply a fungicide containing mancozeb or copper to get the disease under control.
Indoor palms often appear to be suffering from disease, but in reality they simply have a nutritional deficiency. For example, bronze, yellow, brown and black spots on leaves indicate that your indoor palm tree needs a dose of potassium and magnesium fertilizers. On the other hand, yellow bands across the leaves can be treated with magnesium alone. If your palm is black and stunted, then it needs calcium in the form of a calcium nitrate or sulfate fertilizer.