Emerald Ash Borer
Emerald Ash Borer (EAB) is an invasive insect pest that aggressively spreads and kills green ash trees. EAB was confirmed in Fridley in 2019, and since then outbreaks have been confirmed throughout the city. The larvae of EAB tunnel under tree bark, which interrupts the flow of water through the tree. Once symptoms are present, the ash tree typically dies within one to three years. If you have an ash tree on your property, act now to treat or remove it before the tree becomes a safety hazard. If you are planning to treat your tree, start now.
Ash Tree ID
Ash trees are one of the most common shade trees in Fridley. An estimated 30% of the City's publicly owned trees are ash with thousands more located on private property. To tell if you have an ash tree, look for:
- Diamond- patterned bark on mature trees
- Leaves and branches that are opposite each other
- Leaves comprised of small leaflets
What to Do About EAB?
If you have an ash tree in your yard, assume that it will become infested with EAB and die without intervention. Due to the ubiquity of ash trees throughout the city, the impact of EAB in Fridley will be devastating without resident help. If you have an ash tree, you may choose to:
1) Treat your ash tree
2) Remove (and replace) your ash tree
Due to the shade, air quality, and water quality benefits provided by mature trees, the City recommends treating ash trees that are:
- Over 10 inches diameter
- In a good location
- Not exhibiting advanced EAB symptoms (>30% canopy loss)
Although trees must be treated every 2-3 years, it is usually more cost efficient to treat the tree long-term than remove it.
Treating Your Ash Tree
You can protect your tree against EAB infestation using chemical treatment. Chemical treatment must be reapplied every two to three years. Do not wait until the tree is exhibiting symptoms of EAB to start treatment as the damage may be irreperable and the tree too far gone. Treat the tree using a systemic chemical injected by a Fridley-licensed tree company. Some chemicals used to treat EAB can be harmful to beneficial insects such as pollinators if applied improperly. Systemic injections are the most effective form of treatment and are the least likely to adversely impact pollinators. Avoid using treatments that are applied as soil drenches, which can leach into water or drift to pollinator habitat.
As part of the City's contract with Rainbow Treecare, Rainbow is offering Fridley residents bulk pricing discounts on treatment ofrivate ash trees at a rate of $5.00- $5.50 per diameter inch.
Ash Tree Removal
As EAB infestation progresses, the tree dies and becomes a safety hazard. Removing a dead tree is more difficult and expensive than a living tree, so early removal is recommended. Do not remove ash trees during EAB flight season (May 1- September 30) unless the tree poses an immediate safety concern.
If you remove an ash tree on your private property, make sure to replace it in order to protect Fridley's urban ecosystem. Check out this list of recommended replacement trees from the University of Minnesota Extension.
City of Fridley Emerald Ash Borer Mitigation Plan
The City is currently managing ash trees on public lands and right-of-ways under the City of Fridley EAB Mitigation Plan. This plan was developed to prevent the spread of EAB, save high value ash trees, diversify the City's urban forest, and reduce the costs of tree removal. The full plan can be viewed here.
The City is removing and replacing poor quality ash trees and treating high quality ash trees. We will contact the adjacent property owner before removing or treating an ash tree in a front yard boulevard. If you are wondering the status of an ash tree in your boulevard, please call 763-572-3594.
Symptoms of EAB do not appear until the infestation is advanced. Do not wait until symptoms appear to start treating your tree. Symptoms of advanced EAB infestation include:
- Leaf dieback resulting in canopy thinning
- Increased woodpecker activity due to woodpeckers eating the EAB larvae
- Ash blonding in which the lighter colored wood is exposed due to birds peeling away the outer bark looking for larvae
- D-shaped exit holes under the bark
Have you seen an ash tree that might be infested? Report a Tree Concern.