Taking action

Ash mortality in Central Wisconsin

Michael Hillstrom, forest health specialist, Fitchburg. michael.hillstrom@wisconsin.gov, 608-513-7690

Forest health has relayed the message over the last few years that stand level ash mortality from emerald ash borer (EAB) is occurring in southeast Wisconsin and along some parts of the Mississippi River. Those areas of mortality continue to progress each year, but stand level mortality is no longer limited to just these areas. 

All the ash in this stand near Roche-A-Cri State Park in Adams County are heavily flecked by woodpeckers feasting on EAB larvae. Extensive flecking indicates EAB has fully infested these trees and mortality is imminent. Photo by Mike Hillstrom.

February and March are good times to look for woodpecker damage to ash trees (known as “flecking”), and potentially find new EAB infestations or expansions of known infestations. Winter scouting has allowed us to detect ash mortality from EAB in unexpected places. I was in Adams County in mid-February looking for EAB biocontrol release sites.  I was shocked to find a stand where all the ash trees were heavily flecked and likely dead or close to it.  We had not previously confirmed EAB in that township or any of the townships directly surrounding it.

This incident further drove home the point for me that even isolated patches of ash are not safe from EAB. We are now past the point of thinking about taking action in ash stands in southern and central Wisconsin; we must now move forward with site assessments, with salvage/pre-salvage harvesting being a high priority for management.  In addition, non-ash regeneration growing should be started sooner rather than later. Of course, in urban settings, now is the time to prophylactically treat high-value ornamental ash trees.

The EAB silviculture guidelines will be revised in 2018; stay tuned.


Prepare now – gypsy moth caterpillars return

Gypsy moth caterpillar with distinctive blue and red dots

Gypsy moth caterpillar with distinctive blue and red dots

This June, gypsy moth populations may rise to damaging levels in parts of Wisconsin. High numbers of gypsy moth caterpillars are a tremendous nuisance and can strip trees of their leaves. Combined with other stresses, such as drought or attacks by additional tree pests, this may kill the tree. The insect’s favorite food is oak leaves, but it will feed on many other tree species such as aspen, birch, crabapple and willow. You can take action to reduce the number of caterpillars that will feed on your trees, including placing sticky barrier bands on the susceptible tree species. Continue reading “Prepare now – gypsy moth caterpillars return”

UW-Stevens Point students gain real world skills while helping communities

In an attempt to find an avenue to get small communities in the fold of beginning, or better managing their community tree resources DNR Regional Urban Forestry (UF) Coordinator, Don Kissinger, resurrected memories of his college days when he and his classmates were given a computer simulation to react and manage a fictitious community forestry program. Through this attempt the collaboration with UW- Stevens Point Professor Rich Hauer and his senior level Urban Forestry Lab class began.

Continue reading “UW-Stevens Point students gain real world skills while helping communities”

Amur cork tree is an emerging threat to Wisconsin forests.

Amur cork tree (Phellodendron amurense) is a relatively new invasive plant found in at least four Wisconsin counties. It is classified as Prohibited under Wisconsin’s invasive species law, NR 40. The female cork tree cannot be possessed, transferred, transported or introduced in Wisconsin. We ask that you report this tree to DNR because it is invasive here and in other states and DNR is mounting control efforts before it becomes widespread. DNR works with property owners to achieve this by providing advice, tools and resource opportunities. Continue reading “Amur cork tree is an emerging threat to Wisconsin forests.”

Oil or remove gypsy moth egg masses now

Gypsy moth egg masses are tan colored lumps about the size of a nickel or a quarter. They are usually found on trees but may also be found on outdoor articles such as firewood piles, bird houses and picnic tables.

Gypsy moth egg masses.

Homeowners who are interested in reducing gypsy moth caterpillar numbers this summer should consider oiling or removing reachable egg masses well before the eggs begin hatching in the second half of April. Gypsy moth egg masses are tan-colored lumps about the size of a nickel or quarter, and usually contain 500 to 1,000 eggs. The egg masses can be found on any rough or protected surface including trees, houses, firewood piles, bird houses and other outdoor objects. Do NOT scrape the egg masses onto the ground or step on them or break them apart. Many of the eggs will survive and still hatch.

Continue reading “Oil or remove gypsy moth egg masses now”

Treat your ornamental ash trees for emerald ash borer this spring

A yellow ornamental ash tree at peak fall color. This tree is worth treating to protect it from being killed by emerald ash borer.

High-value ash tree at peak fall color.

March is a good month to consider insecticide treatments for high-value ornamental ash trees this spring. Emerald ash borer (EAB) has been found in 42 Wisconsin counties and is expected to be more than 99% fatal to ash trees that are not protected with insecticide every 1-2 years. Many insecticides used in EAB treatments are applied between mid-April and mid-May, and now is a good time to contact a tree service or other pesticide application business if arranging for professional insecticide treatments.

Property owners with susceptible ash trees should consider a number of factors when deciding to treat their ash trees, including financial cost, tree condition and location, the shade a tree provides, its contribution to property values, and aesthetic view. Homeowners should also consider the financial cost of removing a tree that is killed by EAB, and the benefits that a dead tree no longer provides.

Continue reading “Treat your ornamental ash trees for emerald ash borer this spring”

Finding bird friendly trees

If you are looking for bird friendly trees and shrubs a database has been created that can help. The Audubon Native Plants Database allows you to enter a zip code and get a list of bird friendly native plants. You can filter based on plant type and what type of bird the plant attracts. The database also shows what kind of birds favor particular plants.


For more information contact Ellen Clark (EllenA.Clark@Wisconsin.gov), Urban Forestry Communication Specialist, at 608-267-2774.


Urban Forestry supports health care research

The University of Illinois is taking the lead on a three-year research project exploring urban forestry’s effects on health care spending.  The project will be the first to focus specifically on urban forestry’s economic return on investment.  Health expenditures of over 4 million people will be analyzed with LiDAR (Light Detection and Ranging) canopy coverage.  The project will also result in a free, online tool that can be used to estimate a community’s return on investment for their urban forest.

For more information contact Ellen Clark (EllenA.Clark@Wisconsin.gov), Urban Forestry Communication Specialist, at 608-267-2774.