American elm (Ulmus americana) is a native tree species in North America, and it is not considered invasive according to state and national invasive species lists. This means that it does not pose a significant threat to the environment or native ecosystems in the same way that invasive species do.
In my personal experience as a gardening and landscaping expert, I have found American elm to be a beautiful and valuable tree for many landscapes. It has a tall, graceful shape and attractive, serrated leaves. The bark is also visually appealing, with a distinctive gray color and rough texture.
One of the reasons why American elm is not considered invasive is because it has evolved alongside other native plant and animal species in its natural range. This allows for a balance to be maintained in the ecosystem, with the elm tree providing food and habitat for various organisms.
However, it is important to note that American elm has faced significant challenges in recent history. Dutch elm disease, caused by a fungal pathogen, has decimated many populations of American elm trees across North America. This disease is spread by elm bark beetles, and it can rapidly kill infected trees.
In the past, American elm was commonly planted along city streets and in urban areas due to its tolerance of urban conditions and its aesthetic appeal. Unfortunately, this also made it more susceptible to Dutch elm disease, as the beetles could easily spread the disease from tree to tree.
Efforts have been made to develop and plant disease-resistant varieties of American elm, such as the ‘Princeton’ and ‘Valley Forge’ cultivars. These trees have shown some resistance to Dutch elm disease, giving hope for the future of American elm populations.
While American elm is not considered invasive, it is still important to be mindful of the ongoing threat of Dutch elm disease. When planting American elm trees, it is important to choose disease-resistant varieties and to monitor for any signs of disease. This can help to protect these beautiful trees and ensure their continued presence in our landscapes.
