Answer: Ficus trees are attractive with their graceful, delicate branches, but they can be quite finicky. Nearly any change in environmental conditions is an excuse to drop leaves. Since the symptoms are occuring during the winter months, it's a good bet that the problem is excessive moisture or reduced light levels or both.
Before you water next time, check the soil moisture in a couple of spots by poking your finger an inch or two into the pot. Let this be your guide to watering rather than the appearance of the soil. In our heated homes, the upper surface of the soil dries out rapidly, and its appearance can be deceptive. When you water, be sure the excess can drain away. If roots sit in wet soil they die, and that also causes leaves to drop.
Decreasing light intensity during winter also causes leaf-drop. It may helpful to move the plant to an area with more light. Ficus benjamina may also drop leaves in response to being moved. Other causes of leaf-drop include not watering enough, the presence of scale or other insects, compacted soil, and the need for repotting.
Best wishes with your ficus!
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