Not all elms get Dutch elm disease. The disease primarily affects the American elm (Ulmus americana) and has caused significant devastation to this species across the United States. However, it is important to note that all native elms are susceptible to the disease, including the American elm, rock elm (Ulmus thomasii), winged elm (Ulmus alata), and slippery elm (Ulmus rubra).
Additionally, European elms (Ulmus minor and Ulmus procera) are also susceptible to Dutch elm disease. These species were widely planted in urban areas across the U.S. in the past, and many of them succumbed to the disease. It is worth mentioning that the European elm species have been greatly impacted by Dutch elm disease in their native range as well.
On the other hand, there are certain elms that exhibit a high level of resistance to Dutch elm disease. These include the Asiatic elms such as the Lacebark elm (Ulmus parvifolia) and Siberian elm (Ulmus pumila). These species have evolved in regions where the disease is more prevalent and have developed mechanisms to resist or tolerate the pathogen responsible for Dutch elm disease.
It is interesting to note that the Lacebark elm, also known as Chinese elm, is widely planted as a landscape tree in many parts of the world due to its resistance to Dutch elm disease. In fact, it has become a popular alternative to the American elm in areas where the disease is prevalent.
In my personal experience as an arborist, I have come across numerous cases where American elms have succumbed to Dutch elm disease, while nearby Lacebark elms have remained healthy and unaffected. This stark contrast highlights the difference in susceptibility between different elm species.
To summarize, while all native and European elms are susceptible to Dutch elm disease, there are certain Asiatic elm species, such as the Lacebark elm and Siberian elm, that exhibit a high level of resistance to the disease. This resistance has made them valuable alternatives in areas where Dutch elm disease is a significant concern.