Hi Susan,

There could be a couple of reasons why the leaves are turning yellow.

How often do you feed the plant? There is not much soil in your pot and the nutrients in the soil are quickly depleted. Fertilize monthly in the spring and summer, when the tree is actively growing, with a balanced plant food diluted to 1/2 the recommended strength.

Under watering: Ficus plants lose yellow leaves when they are not getting enough water. Now that your plant has grown for several years and I assume it is in the same pot, it needs more water.

Try fertilizerPlants need fertilizer only when they are actively growing. Slow growing plants in low light require very little plant food. Too much fertilizer is worse than not enough. Most plants prefer a water soluble plant food at 1/2 the recommended strength. Plants that are in bloom or dormant should not be fertilized. Houseplant food contains nitrogen (N), phosphorus (P), and potassium (K). A fertilizer containing these elements in equal proportion is considered a balanced plant food. Nitrogen helps in photosynthesis and encourages the growth of leaves and stems. Potassium and phosphorus also help in photosynthesis and aid in root and flower development. Most fertilizers have trace elements of other minerals that are lacking in the soil but are necessary for good plant growth. Fertilizers have a high salt content. If a plant is not producing new leaves and doesn’t absorb the fertilizer, salts build up in the soil. These salts can burn the roots, discolor the leaves, and cause new growth to be small.   and water an see if it helps the problem.