About Osseo

Ash Tree Preservation

Ash Tree Preservation

Ash Tree Preservation

What is EAB?

The Emerald Ash Borer (EAB) is an invasive beetle from Asia. It was first discovered in the United States during the summer of 2002 near Detroit, Michigan. EAB has quickly become one of the most destructive and costly forest insects in urban forest history.

EAB larvae feed on the inner bark of ash trees which disrupts the tree‘s ability to transport water and nutrients. Once an ash tree is infested, it has almost zero chance of survival. The only way to protect your trees is with treatment.

EAB populations can grow exponentially each year because the beetle has few natural predators and our ash trees have limited natural defenses. When EAB is not managed, annual ash tree deaths can quickly overwhelm the resources required to remove dead and dying trees. The good news is that healthy ash trees can be protected against EAB.



What is the City doing?

In 2019 the City funded a tree survey of the city's publicly-owned* tree population. This survey found there are 120 ash trees within the city boundaries.

Today, Osseo has contracted with the company Rainbow Treecare to provide preventative treatments to the city's publicly owned Ash trees. These treatments are injections, lasting for two years, which make it impossible for the EAB larvae to feed and spread, saving the Ash tree. However, these treatments can only be administered while the tree is either completely healthy or suffering from the very early stages of infestation. In order to determine which of the city's trees can receive treatments, teams from Rainbow Treecare are visiting the trees identified in the 2019 study to determine their status. Any trees able to be saved will receive treatment.

*publicly-owned trees are those located on public land or in the right-of-way, generally 10-15 feet behind the curb line.

What about private trees?

As a condition of the contract, residents of Osseo that would like to have treatments applied to their privately-owned Ash trees may partner with Rainbow Treecare at a discounted rate. Residents will have to contract with Rainbow Treecare directly, and Rainbow Treecare will honor the discounted rate at any Osseo address. Rainbow Treecare can be contacted using the link or contact information below. Rainbow Treecare offers no-cost consultations.

Rainbow Treecare

This agreement does not include a discount for the removal of infested, dying, or dead trees.

Hennepin County provides these resources on assessing your private trees. Find those resources here:
Identifying Ash Trees
Decision Tree Guide
EAB Brochure


Who is Rainbow Treecare?

Rainbow Treecare, founded in 1976, is a Minnetonka-based tree care company that has been administering EAB treatments since 2004. They've since partnered with over 35 metro area cities to preserve and manage the local ash tree populations.


Why is this important?

More than 1 in 5 of the metro area's trees are ash trees. Statewide, Minnesota has an estimated 937 million ash trees.

As EAB's rate of spread grows exponentially, each one of those trees is at risk of infestation. Beyond the ecological damage and damage to the visual aesthetic of the city, each dead tree poses a significant risk of falling and damaging the area around it.