Q.Begonia Gryphon
I bought a Begonia Gryphon a year ago. It was growing very nicely and very full. I brought it inside last winter and the leaves became a little sparcer but I thought it would fill out again in the spring when I put it back outside. Unfortunately, it has not. The main stalks are growing well but it has only about half the leaves it originally had. Does this plant need to be repotted as it grows or is there something I can do to improve the fullness of the plant? I have it in an urn in the original pot I bought it in and it gets full shade most of the day with just a little filtered sun in the afternoon.
You can, or you could overwinter it outside in a sheltered location. It may also help to wrap the pot it's currently in with bubble wrap to help insulate the plant roots. When wintry weather is expected, adding a blanket over top can also help. Here is more information on overwintering begonia plants: https://www.gardeningknowhow.com/ornamental/flowers/begonia/wintering-begonias-overwintering-a-begonia-in-cold-climates.htm