Siberian Elm, Ulmus Pumila
This tree is considered the hardiest of all elms. It is a fast growing tree that is native to northern China and eastern Siberia. It is highly invasive and considered undesirable as it seeds prolifically, has a high germination rate and is susceptible to many insects and disease problems. However, it can adapt to very difficult sites and is tolerant of drought and poor soils. As a single specimen and maintained properly, it can be a nice tree. It can reach a height of 70 feet with a spread of 50 feet.