China doll plants are evergreen trees that are a part of the Bignoniaceae family. They are moderately fast growers reaching heights between 4 and 6 feet at maturity. The most important thing to remember is that they require lots of light and moisture and do not react well to frequent changes in their growing conditions. Leaf drop commonly occurs if their growing conditions are not right or change too quickly. Regular watering is vital, water once the top inch of soil is dry, the frequency of which will vary depending on the season and environment in your home.