Question
What causes the leaves of a Ficus plant to turn brown?  The plant is sitting next to a window.  I water it about once a week.  It is about 4 feet tall.  I've had it about 4 years.  Some of the leaves have brown spots and some have huge brown sections.  Some of the leaves are perfectly fine.

Answer
Judy,

I suspect that the spots you are are talking about are actually an insect called scale. It looks like a little black, brown or gray dots on the back sides of the leaves and you can scrape them off with aq fingernail or a sharp knife. A large infestation of scale can cause leaves to turn brown and fall off.

You can kill the scale by flicking each one off the plant with a q-tip soaked in rubbing alcohol. If there are too many for that you can also put rubbing alcohol mixed 50/50 with water and add 2 teaspoons of dish soap per quart of mix in a spray bottle and spray the entire plant twice a week for 6 weeks and it will kill the scale insects but you must be consistant with the spraying or babies will hatch from eggs and keep re-infesting the plant. If you have more questions or if you find you do not have scale feel free to write again. Good luck.

Darlene