Trees are beautiful. Trees produce oxygen. Trees absorb carbon. Trees are wonderful. …except for the Siberian Elm.
The Siberian Elm (Ulmus pumila) in the Western United States is a weed on steroids. My family had a two of Siberian Elm trees in our front yard in northwestern Colorado, where I grew up, but we incorrectly called them a Chinese Elm. They are commonplace in most towns throughout the West, but typically they only grow in areas that are neglected.
The Siberian Elm was introduced in the United States in the 1860’s, and is now considered an invasive tree. It is primarily found in less affluent neighborhoods. It is a fast growing, rapidly spreading tree, that withstands cold winter climates. Once its root system is established the only way to kill it is to destroy the root system or girdle the tree.
Until recently, the Siberian Elm was sold as a plant to create a hedge. Its fast growing characteristics made it attractive to homeowners that wanted a quick barrier at the edge of their property.
Unfortunately, once established, its growth becomes an enemy to the homeowner and her or his neighbors. It requires constant trimming, and once out of control it reverts to its natural tree behavior by shooting up branches that can grow six feet or more per year.
As a mature tree, it typically will have large branches die that make the tree look trashy unless it is constantly maintained.
The Dandelion of Trees
The worst part of a Siberian Elm is its ability to spread. In the early Spring the tree will almost look as if it has dead leaves. These are not leaves but masses of rounded, flat seeds that cover the ground once released. These white to slightly yellow seedlings will blow around until they find a spot to take root. By the end of the summer, there will be thousands of new saplings growing anyplace that is neglected.
This is probably why the Siberian Elm is found in poorer neighborhoods. The tree thrives in areas where yard care is ignored and it has the opportunity to establish a root system before it can be cut or pulled. Once established, the root system will send up new saplings, that will continue to grow until it is dug up, or until a mature tree is established.
By mid-summer, Siberian Elm trees can be infested with bugs. The Elm Leaf Beetle (Xanthogaleruca luteola) is the most common pest. Both the larva (Spring) and the mature beetle (mid-Summer) will riddle the leaves of the tree with holes. By Fall, the leaves add to the trashy look of the tree or hedge.
A 2014 U.S. Forest Service publication suggested that more public education of the invasive nature of the Siberian Elm is needed; however, communities throughout the Southwestern United States may want to take stronger action, as the Siberian Elm is a mark of shame in any neighborhood.