ficus leaves turning yellow
i have a grouping of five small ficus plants. maybe 9 or 10 inches tall in a bonsai pot. i have had this for over three or four years. i have never re-potted the plants because they looked so healthy. i have meant too, but never did. just last week, i started seeing a lot of yellow leaves. one of the plants has lost almost all it's leaves. i cut a few branches that lost leaves, the inside was green but no white sap.
so, should i re-pot the plants? should i take the plants out that lost most of the leaves and put them in a soil mixture and see if they come back?
maybe re-pot and use three of the five most healthy?
it seems that this happened over night. the plants have been sitting on our windowsill all this time with morning sun. only a few time has it been outside.