I apologize for this delayed reply to your gardening question and hope it is still helpful to you.
The yellowing leaves are due to various stresses. Dry soil, soggy wet soil, and a lack of light can all cause yellowing of the foliage. I suggest you put it outside in a very bright shade and then gradually over a week or so move it to full sunlight. Then begin to fertilize it with a soluble plant food like Miracle Gro following label instructions.
Thanks for the question. Best wishes for a wonderful gardening season. Please stop in again soon!
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