Protecting Your Trees From Winter Freeze

Learn about how trees prepare for the winter cold, and what steps you can take to help them!

Select this article:  Protecting Your Trees From Winter Freeze


Trees in the Right-Of-Way

In the past, the responsibility for the maintenance of trees in the City right-of-way (typically the area between the street and sidewalk in most areas of the City) has been the responsibility of the adjacent property owner. Under City Code John Olds, Urban Forestry Supervisoradjacent property owners had the responsibility for maintaining a minimum tree clearance height of 14’ over a city street and an 8’ minimum height over sidewalks. The height clearances also pertain to trees planted on private property.  State law has dictated that all trees planted within the public right-of-way that are dead, diseased and dying are the responsibility of the City.  Many residents have been diligent with the trimming of the trees planted in City right-of-way but issues with clearance and maintenance have continued to be an issue.  

Tree clearance issues create on-going problems for traffic, pedestrians, school buses and solid waste collection. Various operations performed by Public Services staff such as snow plowing and street sweeping have also been impacted.

To minimize many of the issues associated with the maintenance of City trees in the public right-of-way, the West Des Moines City Council approved modifications to the City Code at the December 27, 2016 Council meeting that shifts the maintenance of these trees from the adjacent property owner to the Public Services Department. Keep in mind that this only applies to trees planted within City rights-of-way; trees planted on private property are still the responsibility of the property owner to maintain.


In addition to trimming trees planted in public rights-of-way, the Urban Forester and Public Services staff will also be removing damaged or dead trees and vegetative material that poses an immediate risk to public safety and/or adjacent property or infrastructure.  For the purposes of scheduling and assigning locations, crews will work through zones utilized with the City’s Street Cleaning program.  The goal for the City’s approximate 6,400 public trees will be to evaluate and, if necessary, trim on a three year rotation.  Any private trees on the list will be referred to the West Des Moines Community Compliance officers to address in the appropriate manner.  Public as well as private trees provide numerous benefits to our community and with proper and routine maintenance should continue to do so for years to come.


Emerald Ash Borer (EAB)

**New Detection of EAB Discovered in Polk County**

Emerald Ash BorerAbout Emerald Ash Borer
The emerald ash borer (EAB) is an invasive insect that has killed tens of millions of ash trees  since it was first discovered in 2002.   EAB kills all ash tree species and is considered to be one of the most destructive tree pests ever seen in North America. Trees are killed when high enough numbers of larvae burrow under the bark and girdle the trees by eating the actively growing layers. Once infested, the tree will typically die within two to four years.

Infestations in Iowa
The first confirmed occurrence of EAB was in May 2010 on an island in the Mississippi River in Allamakee County. Despite extensive trapping and the examination of hundreds of declining ash trees the pest was not seen again until July 2013 in Burlington in Des Moines County. Since then EAB has been confirmed in a total of 22 Iowa counties, with Polk County being the most recent discovery in May of 2015.  EAB was confirmed in a residential tree in West Des Moines and in a public tree in Urbandale. 

The entire state of Iowa was placed under quarantine on February 4, 2014.  Hardwood firewood, ash logs, wood chips, and ash tree nursery stock cannot be moved out of Iowa into a non-quarantined area of another state.  These materials can be moved anywhere within the state of Iowa, but residents are urged to not move firewood long distances.  This will slow the spread of EAB to areas that are currently EAB-free.

Ash Trees on Public Propertyeab plan cover
Well before EAB was confirmed in Polk County, the City of West Des Moines was proceeding with implementation of the City's EAB Management Plan as if the insect was already here. 
The Parks & Recreation Department assessed all public ash trees. These include over 1,100 trees in parks, street right-of-way, street medians, and around city buildings. This information is being utilized by the City's Urban Forestry Supervisor to schedule pre-emptive ash tree removals. Preventative treatment of over 600 public ash trees began in May, 2015.  Most trees removed from City parks, medians, city facilities and parking lots will be replaced using a variety of species from the Iowa Department of Natural Resources Ash Replacement List. Trees removed from street right-of-way will not be replaced by the City.  Replacement of street trees by adjacent property owners will likely not be possible where underground utilities are present or where space is limited. For more information on EAB and ash trees on public property contact our Urban Forestry Supervisor, John Olds, at 515-222-3417 or

Steps for Private Property Owners
• Identify any ash trees on your property.
• Look for possible signs of EAB – sprouts on the trunk, dead or dying tree canopy, excessive woodpecker activity, and/or the presence of EAB larvae or adult insects.
• If you suspect EAB, contact one of the Iowa EAB Team members listed below.
• If EAB is confirmed, it will be the property owner’s responsibility to remove dead and dying ash trees on private property. To find a qualified tree care professional, check out the ISU Extension List of Certified Arborists.
• Treatment options are available and may be a good choice for protecting your ash tree. For information on the latest EAB treatments visit Iowa Department of Natural Resources EAB website
Tragically, EAB is going to alter every community's landscape as well as the composition of our native woodlands for many years. 

To learn more about EAB, please visit For more information about EAB in West Des Moines, contact John Olds, Urban Forestry Supervisor, / 222-3417.

 Other Resources

Iowa EAB Team Members

 Robin Pruisner    IDALS State Entomologist  515-725-1470 
 Mike Kintner     IDALS EAB Coordinator  515-745-2877 
 Paul Tauke DNR State Forester  515-725-8450 
 Tivon Feeley DNR Forest Health Coord  515-725-8453 
 Jesse Randall ISU Extension Forester  515-294-1168 
 Mark Shour ISU Extension Entomologist  515-294-5963 
 Laura Jesse ISU Extension Entomologist 515-294-0581
 Donald Lewis ISU Extension Entomologist 515-294-1101
 Jeff Iles ISU Extension Horticulturist 515-294-3718


WDM City Ordinance - Title 7, “Public Ways and Property”, Chapter 10, “Trees and Shrubs”

Iowa Department of Natural Resources EAB Website

Managing EAB: Decision Guide


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