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Emerald Ash Borer Management

What is emerald ash borer?

Emerald ash borer (EAB) is a non-native, invasive insect that attacks and kills ash trees. It can be spread through transported firewood.

The adults are small, iridescent green beetles that live outside of trees during the summer months. The larvae are grub or worm-like and live underneath the bark of ash trees. Trees are killed by the tunneling of the larvae under the tree's bark. 

Residents can help slow the spread of emerald ash borer by not transporting firewood and by disposing of trees locally. 

Scott County is currently under a quarantine by the Minnesota Department of Agriculture. This means people cannot transport any hardwood from Scott County to a non-quarantined county. 

More Emerald Ash Borer Resources

What should I do if I have ash trees on my property? 

Do not treat or remove boulevard or park trees without permission from the City.

Contact Natural Resources at 952-233-9382 or ktemplin@ShakopeeMN.gov.
 
Treatment Options
There are chemical options which have proven effective for protecting ash trees against emerald ash borer. If you desire to save your ash tree, you should begin treatment in the spring. 

City-owned ash trees (within right-of-way and parks) will be treated by a private contractor. To promote proper treatment on private property, the City offers bulk discounted rates to residents through a contract with Rainbow Treecare.

If you are interested in participating in the City’s EAB treatment program:

The City has ensured Rainbow Treecare meets high standards in staff training and years of experience. Rainbow also has several commercial pesticide applicators and ISA-certified arborists on staff. Treatment offered through this program is a trunk injection of emamectin benzoate, which offers protection from EAB for two to three years.

How long/often will I need to treat my ash tree?
Emerald ash borer’s population is expected to rise and fall in a matter of 10-12 years. Therefore, ash desired to be saved will need to be treated every one to three years (depending on chemical) during this time. After all the non-treated ash have died, emerald ash borer’s food source will be limited, reducing its population. At this point, you should anticipate a longer time between treatments, every three to six years depending on pest pressure.

When do I need to remove an infected tree?
Emerald ash borer has been shown to kill 100 percent of ash trees not chemically treated. It is not recommended to immediately remove all ash trees you do not plan to treat, but you should prepare for it.

  • Start a replacement tree close to the ash you plan to remove. If you have multiple, stage removals.
  • Do not prune or remove a tree during emerald ash borer's active period (May-September).
  • It is more expensive to remove a dead tree than living, and this can be especially true in backyards.
  • Keep a close eye on your ash trees since emerald ash borer-infested trees can go from looking a little thin to dead in a year or two.
  • Contact an ISA-certified arborist if you start to notice a thinning canopy or cracking bark in the upper half of the tree.
What is the City doing with public trees? 
The City manages all trees within the street right-of-way and parks. Public ash trees that meet a certain size, condition and placement criteria are being chemically treated to protect against emerald ash borer. The ash trees which do not meet these criteria are being removed and replaced over a period of eight years.