Diseased Trees

There are many tree diseases to be on the lookout for in Mendota Heights. Some are minor diseases that do not require treatment or affect the long-term health of your landscape trees. However, some are terminal, and require special treatment and prevention, and even quarantine procedures. Diagnosis often requires a site visit by a tree care professional. The following are some of the more common tree diseases that require special care.

Emerald Ash borer is a non-native insect from Asia that feeds on ash trees and disrupts the nutrients and water that flows through the tree, eventually killing it. Mendota Heights is within a Quarantine Area (Dakota County) of Minnesota. This means the movement of any ash wood, or regulated products of ash wood, is prohibited from a Quarantined Area to a Non-Quarantined Area.

Signs & Symptoms

Symptoms of EAB can be easily confused with other ash tree diseases, so it is best to consult a tree care professional if you think you have an infected ash tree. Here are some of the signs and symptoms to look for:

  • Crown dieback
  • Light patches of bark
  • Epicormic sprouting, or new branch and leaf growth on the trunk of the tree or at the base, often excessively
  • Vertical bark splits
  • D-shaped beetle emergence holes
  • S-shaped larval galleries under the bark of the tree
  • Larvae (cream-colored, about 1.5 inches long) under the bark of the tree
  • Adults (metallic green, usually under a ½ inch in length
  • Woodpecker feeding

Prevention & Control

  • Don’t move firewood! EAB can emerge from the infected wood for two years after cutting.
  • Avoid removing, pruning, or cutting of ash trees during the active period (May 1 through September 30)
  • Consult a tree care professional to decide if treating healthy, high-value ash trees with systemic insecticide is a feasible option.
  • Look for signs of EAB
  • Remove infected trees and dispose of wood and debris properly, by sending them to the nearest Ash Tree Waste Disposal Site during the low-activity period (October 1 through May 1), and within your quarantine area.

Removal & Disposal

 After August 1 and before March 31, trees with EAB can be removed and transported within the quarantined area for disposal. There are several approved disposal sites within the area (listed below). Any transportation of EAB material outside of the quarantine zone must be chipped to less than 1”x1”x1” to effectively kill any EAB larvae.

Hire a reliable, insured, licensed arborist or tree service company if the tree is too large to remove yourself.

The wood does not have to go to waste. You can use it around your home in several ways, or even recover some of its value. Here are some of the ways you can use your dead ash trees:

  • Lumber: Local mill operators are sometimes able to bring a portable sawmill directly to your property to be converted to lumber that you can utilize for a variety of projects. Milling is suited to trees killed by EAB, because the insect does not damage the interior portion of the wood.
  • Landscaping: The wood can be milled into timbers, or chipped for mulch for gardening and landscaping.
  • Art or furniture: If you are a wood-worker, or are able to hire one, ash wood is a good substitute for oak, and can be made into a quality piece of furniture or artwork.
  • Firewood: Wood from dead ash trees killed by EAB can still be used for firewood at the location where they were removed.

If you cannot find a way to use your dead ash wood around your home, there are a few options for disposal.

  • Sell your ash wood to reputable buyer, such as a sawmill or other industry. Be sure to require a signed statement that all wood will be handled in a way consistent with the MDA quarantine regulations.
  • Donate the wood. Your ash wood could make a difference in the community, by donating to local schools, parks, or community organizations. One such organization, Wood from the Hood, reclaims wood from all over the Twin Cities, turning wood that would normally be brought to a landfill, burned, or mulched, into quality and environmentally sustainable furniture, lumber, slabs, flooring, cribbage boards, growth charts, and more!
  • If you are unable to use your ash wood, sell, or donate it, there are approved disposal sites within the quarantine area that accept ash wood. The entirety of Dakota County is designated as a quarantine area. The following is a list of some of the sites within Dakota County that accept ash wood.
FacilityContact Phone NumberWho Can Drop Off

B&D Wood Recycling & Composting
6520 280th Street West

612-685-3037 or 507-645-4279Commercial or Residential

5500 Blaine Avenue
Inver Grove Heights

651-450-1501Commercial or Residential
805 Yankee Doodle Road
651-450-1501Commercial or Residential
Rock Hard Landscape Supply
3600 Highway 13 West
952-895-7408Commercial or Residential
S&S Tree and Landscaping Specialists
405 Hardman Avenue
South St. Paul
651-451-8907Commercial or Residential
Specialized Environmental Technologies
1030 Cliff Road
952-736-1915Commercial or Residential
Specialized Environmental Technologies
16454 Blaine Avenue

Commercial or Residential


If you suspect you have EAB infected trees on your property contact the Minnesota Department of Agriculture’s Arrest the Pest hotline a t888-545-6684  or email to report. Note the exact location of the tree and take a digital photo if possible.