Citywide EAB Management Strategies

Emerald Ash Borer Management

Current Year Management Plan: City of Saint Paul Emerald Ash Borer Management Program

Forestry utilizes several management strategies to reduce the population growth of the emerald ash borer (EAB). Strategies such as monitoring and insecticide treatment work to slow the population growth of EAB in Saint Paul; while the structured removal of infested trees allows for a more diverse pallet of new trees to be planted. This multifaceted approach to managing EAB will spread out the cost of management over a longer, more manageable period of time and allow for a more efficient response. The following is a comprehensive list of strategies along with descriptions for reducing the population of EAB. 

Monitoring

  • Forestry staff survey city boulevard trees to identify infested boulevard trees to identify infested public ash trees annually. Staff will also inspect public ash trees for EAB upon citizen request.
  • Forestry no longer surveys private properties for EAB infested trees due to a lack of personnel to complete the survey. However, private property ash trees that die from EAB and become dangerous may still require removal under city ordinance. Please contact a licensed tree care company if you would like to be proactive in managing ash tree(s) on your private property.

Removal

  • Public ash trees that are found to be infested with EAB are a priority for removal.
  • Structured Removal: the removal of blocks of EAB infested ash trees. Once removed, these trees are replaced with a more diverse range of species.

Insecticide Treatment

  • Insecticide treatments have been in use since 2011 on public property ash trees.
  • Treatment of public trees is employed as a means of slowing the population growth of EAB.
  • Criteria for boulevard ash tree treatment:
    • 10–20 inches DBH (diameter at breast height).
    • Good overall health without structural defects.
    • Good growing location with no overhead utility conflicts.
  • Public trees are currently being treated with TREE-age® (active ingredient Emamectin benzoate) via the trunk injection method.
  • Residents who wish to treat the boulevard ash tree adjacent to their property can apply for a free permit and hire a licensed company to do so. 

Outreach

  • The green flagging on ash trees is an outreach effort to create awareness of the large number of ash trees throughout the City. All ash trees are threatened by EAB. While the green ribbons do not indicate that the tree is schedules for removal, since it is susceptible to EAB, it will eventually need to be removed.

Green ribbon on ash tree