Emerald Ash Borer has been called a natural disaster in slow motion. In reality, EAB spreads very quickly because it’s an invasive pest with few natural predators.
The Twin Cities is Especially Vulnerable To EAB
One in five trees in the Twin Cities Metro Area is an ash. They were widely used to replace Elm trees lost to Dutch Elm Disease in the 1970’s. When that fatal disease hit, elms made up nearly 90% of the boulevard trees in the Metro Area. Ash also proved hearty. They’ve outlasted many other species planted at the same time, thriving despite harsh winters, road salt, and changing weather patterns.
That generation of ash trees is now mature. Their loss will be especially noticeable since they are among the largest shade trees in many neighborhoods. It also will take time to determine the best species to replace ash. Certainly, the next generation of trees planted will face even harsher conditions including extreme weather events, crowded city environments, and building construction.
EAB Kills Trees from the Inside Out
If left untreated, a tree infested with this green-colored beetle will die. Furthermore, ash trees become brittle once they die, presenting a safety risk. This leaves ash tree owners with two choices: protect against the pest, or remove the tree.
The Benefit of Hindsight
EAB was first discovered in the US in 2002. Experts think it came from wooden packing material on cargo ships. At the time, there were no cost-effective options to protect ash trees. The pest spread like wildfire, leaving neighborhoods once filled with tree-lined boulevards virtually clear-cut.
Fortunately, the Twin Cities can use lessons learned in areas struck first by EAB. Additionally, better treatments have been developed with enough time to prove positive results. Treating and maintaining an ash tree can now be more cost-effective than removing it. Experts also recommend replanting with a variety of species. Monoculture plantings are great for diseases and pests but can mean big losses when something threatens that type of tree.
EAB in the Twin Cities, by the Numbers
- Minnesota has an estimated 937 million ash trees.
- In the Twin Cities Metro Area, more than one in five trees is an ash.
- Ash trees widely replaced elms, which made up nearly 90 percent of Metro Area boulevard trees before they were lost to Dutch Elm Disease in the 1970s.
- Remove and replace policies in St. Paul and Minneapolis will result in the loss of nearly 60,000 ash trees in those two cities alone.
Learn More
- Residents of our Partner Cities qualify for special discounted pricing on ash tree protection.
- Is My Ash Tree Worth Saving?
- Visit the Emerald Ash Borer Status Map from the MN Department of Agriculture to see where EAB has been found in Minnesota.
