A Special Note About Emerald Ash Borer

Iowa officials active in tracking and combating the spread of Emerald Ash Borer say that the deadly tree pest has been found as close as Urbandale. EAB kills all ash tree species and is considered to be one of the most destructive tree pests ever seen in North America.

Emerald Ash Borer is an exotic insect pest from Asia that has already destroyed hundreds of thousands of trees across the United States. The flattened, creamy white larval stage feeds below the bark of ash trees and cuts off all nutrients to the tree and kills it. Adult borers are small, elongated oval beetles that are metallic green in color. This insect colonizes the top of the ash tree first, then moves down the tree.

Parks Director John Schmitz suggests taking time this winter to decide whether you would like to treat ash trees near your home. The window for treating your ash tree with a trunk injection is mid-May to mid-August. If a Johnston property owner is interested in protecting a valuable and healthy ash tree within 15 miles of a known infestation, they should have landscape and tree service companies bid on work, review the bids and treat during the recommended treatment time. If property owners would like to preserve an ash tree near their home that is in the public right-of-way, please click on this link. The Johnston Parks Department treated 60 healthy ash trees in our greenbelts and parks in 2015.

The State of Iowa will continue tracking EAB's movement on a county-by-county basis. Before a county can be officially recognized as infestedproof of a reproducing population is needed, and an EAB must be collected and verified by USDA entomologists. So far, there are no confirmed cases of EAB in Johnston.

Approximately 18% of trees in Johnston’s public spaces are ash trees. The density in several neighborhoods is even higher, and the loss of all of these trees will have a physical and financial impact on the community.

The city has 1,500 ash trees on city property and hundreds more on private property. The city has been taking a proactive approach to dealing with EAB since 2013. We have already removed more than 200 vulnerable ash trees on city property. Most of the trees removed were in Green Meadows, near Crown Point Community Center, in Dewey Park, and on city right-of-way. In 2013, we added the Urban Forest Crew Leader position to lead our efforts.

For every ash tree on public property that the city has removed, (and we have removed more than 200 already) we are replacing it with at least one healthy tree of a different species. In fact, we have replaced these trees with more than 300 trees of various species. We plan to replace more trees than we are removing.

The first thing that all homeowners should do is assess the health of their ash tree(s). If property owners have any trees that are stressed or unhealthy, now is the time to consider the possibility of removal. These trees will be more susceptible to EAB when it arrives. It also gives a little more time for new trees to grow. The key to any plan you develop is to diversify your tree selection. Multiple species and ages are essential to a healthy environment.


Quarantine Issued

A statewide quarantine, issued on Feb. 4, 2014, remains in place, restricting the movement of hardwood firewood, ash logs, wood chips and ash tree nursery stock out of Iowa into non-quarantined areas of other states.

“We still strongly urge Iowans to not move firewood long distances,” said State Entomologist Robin Pruisner of the Iowa Department of Agriculture and Land Stewardship. “A large portion of Iowa is not showing signs of EAB infestation; let’s keep those areas EAB-free as long as possible by not moving wood that potentially harbors EAB or other tree pests. Be vigilant and report suspicious symptoms in counties that are not yet known to be infested to a member of the Iowa EAB Team.”

The Iowa EAB Team strongly cautions Iowans not to transport firewood across county or state lines, since the movement of firewood throughout Iowa or to other states poses the greatest threat to quickly spread EAB and other plant pests. Most EAB infestations in the United States have been started by people unknowingly moving infested firewood, nursery plants or sawmill logs. The adult beetle also can fly short distances, approximately 2 to 5 miles.