Dutch elm disease (DED), the dreaded disease that devastated tree-lined streets across America, no longer presents the same threat. The Nevada Department of Agriculture lifted its ban on elms last year. The Nevada quarantine on elms began in 1980 in order to prevent the disease from spreading into Nevada.
Historically, the American elm was one of the most widely planted street trees in the East and Midwest, and one of the most susceptible to the disease. Whole avenues were lined with these majestic shade trees. Anyone from the East or Midwest probably remembers their beauty. Their arching canopy covered the streets, providing a vista that epitomized the American town.
DED was first discovered in Ohio in the 1930s. By the 1980s, most communities had lost all their elms, many of which had been growing for more than 50 years.
"Tree-lined streets became shadeless avenues of stumps, and native forests lost millions of trees," wrote Peggy McKie, nursery and landscape program coordinator, Nevada Department of Agriculture, in the fall issue of "Nevada's Horticulture Connection." Because trees were planted in rows along street after street, the disease moved readily from one tree to another, killing them.
Researchers worked for years to develop DED-resistant elm trees. There are now several such varieties available commercially. Most varieties were bred with the East Coast and Midwest in mind, areas that receive far more precipitation and winter moisture, and have better soils than Northern Nevada. Although an elm variety may resist DED, it may not tolerate the harsh conditions in Nevada. If you are an elm fan wanting to plant one, find a drought-tolerant, hardy variety.
Here in the West, we have a very messy, undesirable elm, the Siberian. This is the tree that fills gutters with dime-size paper seed pods in the spring. It is also the tree that is infested with elm leaf beetle and their larvae each year. The larvae eat all the green surface of the leaves, giving the tree a brown, burned look.
The Siberian elm is not on the Carson City Shade Tree Council's list of accepted trees, and is banned from planting in Reno. It is tolerant of DED, but not immune. However, for a glimpse of beautiful American elms, visit the University of Nevada, Reno campus quad. In 1988, some of the elms had to be removed due to DED, but were replaced with hackberry and other disease-resistant trees.
• JoAnne Skelly is the Carson City/Storey County Extension educator for University of Nevada Cooperative Extension.