I bought a Begonia Gryphon a year ago. IÃ¯Â¿Â½d never seen them before and I thought it was an absolutely beautiful plant. Over the winter I brought it into the house because the cold nights seemed to be too much for it. The leaves on the plant became sparser but I thought it would fill out again in the spring when I put it back outside. That has not happened. The main stalks are growing well but there are not as many leaves on it as when I first bought it. The plant is in shade most of the day with some filtered sunlight in the afternoon. I still have it in the original pot that I bought it in. Do these plants need to be repotted as they grow? Is there anything I can do to encourage leaf growth?