Mimosa and Bougainvillea

Comment from Mary Youngs

My Mimosa, planted in a large tub in Spring 2010, was slow to start, but late this year has put out new shoots. However something appears to nibble the ends of the leaf shoots, though I can't see anything. Any ideas?
I have, in the last couple of weeks, put it in to the garage for the winter, where it also spent last winter.
How much water will it need while over-wintering?
Is there anything else I need to do to it?
I bought a Bougainvillea in a plant sale for under £8, and it has been a picture all summer. When frosts were threatened, I put it in the garage with the Mimosa, where it is still full od bloom.
Is there anything I should do with it during the winter months?