Zelkova bonsai plants are known for being resistant to many of the diseases that commonly harm other species. They are typically associated with the broom style. This portrays a deciduous tree that has not been influenced by environmental factors. Zelkova plants are native to China and Japan, and they are related to elm trees. There are two species of Zelkova trees, and both are used to produce bonsai plants.The bark is grey and smooth and the young shoots are reddish at first. The leaves are simple and ovate to oblong-ovate with serrated margins, rough on top and glabrous on the underside. They are dark green throughout the summer, changing to yellow, orange, red and purple in autumn. The leafsize decreases quickly when the zelkova grows in a pot. The Japanese greybark elm is a classic Japanese bonsai and the prototype of the broomstyle, but it can also be styled in other upright shapes. The species can tolerate a slight frost and is easy to care for.