As part of the City's Emerald Ash Borer Management Plan, the City removes or treats public ash trees based on a tree's condition rating. Public ash trees are defined as trees within street boulevards and City-owned property such as parks.
on public ash tree removals and treatments within neighborhood boulevards will be
posted here as it becomes available.
The 2018 ash tree removals have been completed. In 2019, the City will hire a contractor to continue with removal of poor quality ash within boulevards and parks. Residents affected by these removals will be notified by mail.
The 2018 ash tree treatments have been completed. The City plans to continue treatment of healthy public ash trees in 2019. Trees within the boulevard right-of-ways of residential areas are considered public trees Residents affected by treatments will be notified in advance by postcard.
Why are we removing poor quality ash trees?
The City designates trees as "poor quality" when they are structurally unsound, severely stressed or unhealthy in some other way. Poor quality ash trees may be characterized by large cracks in the trunk (shown in photo at right), areas of decay, weak branch structure, low leaf production, sprouting along the trunk, insect damage, and other symptoms.
Unhealthy trees release chemical compounds that some tree-eating insects (such as EAB) can detect and use to find these trees. Because of weakened defense systems, poor quality trees cannot as easily fend off attacks from insects. So removing poor quality ash trees reduces the risk of attracting EAB to an area. Though EAB will infest healthy ash trees, they are attracted more to unhealthy ones.
Removing poor quality ash trees also reduces potential tree hazards to people and property. As EAB feeds on tree tissue, the tree becomes fragile and more likely to fall over or drop large limbs. EAB-killed ash wood rapidly dries out and becomes brittle, so that even a light breeze can topple the tree.
Why are we treating good quality ash trees?
All true ash tree species are vulnerable to infestation by EAB. To protect healthy public ash trees, the City treats them on a rotating schedule. The non-neonicotinoid, trunk-injected chemical treatments will protect trees from infestation for at least two years.