When it grows new leaves, it will form leaves that accommodate the change in light. When you put her out again this summer, she will drop most of these "winter" leaves, and go back to her original size. I can't fathom a change of form of leaf, only the size of leaf. It would be interesting if you could post a photo of what the "new leaf" looks like.

Did you ever learn anything, about the change,IN THE SHAPE,of the leaf form ?

Mine shows this same experience,after,I pruned it well,and brought it inside,for the winter.

Does this possibly indicate a change in the sex of the plant?
Or do these "changed leaves" show effect, in it's abilty to flower?

Because it has no blooms,to date,(first days of summer).

And,the"changed leaves",have not reverted back to original tear drop shape,or dropped, as I had hoped.
With the change in season, returned it outside,remaining potted...
and incresed fertilizer applications ...
Changed leaves are healthy and numerous.

Any info much appreciated

Hi ,
I too have a Hibiscus that is about ten years old and have trained it into a "tree" bush meaning the main stalk is about 5 ft tall and then the top is bushy. But I pruned it 2 winters ago and the shape of the leaves have changed from single fat teardrop shape to a 3 lobe shape and has since not produced any blooms. I am completely baffled.

Hibiscus don't react well to stress. They show all signs of stress in the leaves, by dropping them or their changing shape. From what I have read, their DNA is not very stable. I had a tropical once that had red double flowers, regular teardrop shaped leaves. After a freeze, it came back out with tri-lobed leaves and single flowers.

Especially with the hybrids, there is a tendency to revert to one of the original parent's characteristics after a severe stressing event.

Plus, there is always the possibility that if it was a grafted hibiscus, it froze or was cut back to the original rootstock.