When do wax plums with cold and proud frost usually bloom, shed leaves and transplant? Is it suitable to keep it indoors? Can I be grafted?

Chimonanthus, also known as Chimonanthus, Stone Herbal Tea, Tangmei, Xiangmei, is a deciduous shrub, often clustered. So when does it usually blossom, shed leaves and transplant? Is it suitable to keep it indoors? Can I be grafted? According to Chimonaceae