Hibiscus Leaves Turning Yellow Indoors

Q: I am trying to hold on to a tree hibiscus that bloomed beautifully all
summer. I moved it inside when cold weather approached. It is in front of a
window but the leaves are slowly turning yellow. 

A: I think low light is responsible for the leaf drop, even though it’s in front of
a window. Like a lot of plants, hibiscus aborts leaves when light changes from
high intensity to low. Light levels indoors are hundreds of times less than
outdoors. The best you can do is to consider adding a fluorescent or LED plant
light. Make sure the hibiscus is not in a draft caused by window currents or
furnace vents.