City Forester

The City of Mahtomedi contracts with Steve Schumacher, ISA Certified Arborist of Forestry Resources Consulting, whose focus is to control and prevent tree diseases and identify hazardous trees.  If you have a question about the health of your tree call Steve at 651-747-3736.

Emerald Ash Borer Discovered in Mahtomedi

The City of Mahtomedi encourages residents to look for signs of Emerald Ash Borer

The Minnesota Department of Agriculture (MDA) confirmed an emerald ash borer (EAB) infestation in the City of Mahtomedi. A local business reported an ash tree with bark cracks and woodpecker damage in the tree canopy, a tell-tale sign of possible EAB infestation, to the MDA for confirmation.

There are several things residents should look for when checking for emerald ash borer. 

  • Be sure you’ve identified an ash tree. This is an important first step since EAB only feeds on ash trees. Ash have opposite branching – meaning branches come off the trunk directly across from each other. On older trees, the bark is in a tight, diamond-shaped pattern. Younger trees have a relatively smooth bark.
  • Look for woodpecker damage. Woodpeckers like EAB larvae and woodpecker holes may indicate the presence of EAB.
  • Check for bark cracks. EAB larvae tunneling under the bark can cause the bark to split open, revealing the larval (S-shaped) tunnels underneath.
  • Contact a professional. If you feel your ash tree may be infested with EAB, contact a tree care professional, your city forester, or the MDA at or 888-545-6684 (voicemail).


Emerald ash borer larvae kill ash trees by tunneling under the bark and feeding on the part of the tree that moves nutrients up and down the trunk. Minnesota is highly susceptible to the destruction caused by this invasive insect. The state has approximately one billion ash trees, the most of any state in the nation. 

The biggest risk of spreading EAB comes from people unknowingly moving firewood or other ash products harboring larvae. There are three easy steps residents can take to keep EAB from spreading:

  • Don’t transport firewood. Buy firewood locally from approved vendors, and burn it where you buy it;
  • Be aware of the quarantine restrictions. If you live in a quarantined county, be aware of the restrictions on movement of products such as ash trees, wood chips, and firewood; and,
  • Watch your ash trees for infestation. If you think your ash tree is infested, go to for resources on identifying EAB, how to hire tree care professionals, and insecticide options for protecting your ash tree. 

For more information on emerald ash borer, go to


Protecting Trees From Construction Damage (PDF)

What's The Deal With Dutch Elm Disease and Oak Wilt (PDF)
Identify, Prevent and Control Oak Wilt (PDF)
Disposal and Storage of Wood from Diseased Elms and Red/Pin Oaks (PDF)

Emerald Ash Borer Update (PDF)
Emerald Ash Borer Quarantine Emergency Jan 2021 (PDF)
MN DEPT OF AG Emerald Ash Borer (PDF)
MN DNR Emerald Ash Borer Information (MN DNR Website)
University of MN Emerald Ash Borer Question and Answer (Website)

MN DEPT OF AG Brown Marmorated Stink Bug (PDF)

MN DEPT OF AG Arrest the Pest (PDF)

Twin Cities Urban Forest Summary (PDF)
Urban Climate Framework (Website)

Mahtomedi Recommended Tree List (PDF)
Best Planting Practices for Potted Trees (PDF)

Tree Species List to Compartmentalize (Website)