Ficus tree outside
My ficus leaves are suddenly turning yellow! What can I do? It is outside, shaded and hasn't been moved for several years.f
The yellowing leaves could be due to watering issues, light change, insects, or fungus disease.
Is your Ficus in a container? If your watering has not changed, perhaps the plant needs repotting. It may need a slightly larger container--no more then 2" larger, and new soil.
If your tree is root bound and has not enough soil to properly give the tree water and nutrients.
Here is a link with more information.