August 30, 2000
Oak wilt concerns area citizens
Pockets of devastating disease found in five local townships
By Carol South
Special to the Herald
Fourteen trees in three years.
That's how many red oaks have died on David and Alice Fink's property, succumbing quickly and dramatically to oak wilt, a disease similar to Dutch Elm disease that devastated those trees in many areas.
As the Finks walk their 80-acre, wooded spread in Interlochen these days, they worry about the remaining red oak trees. They have learned that oak wilt is a disease spread by fungus spores either directly though a tree's roots or by beetles carrying the spores from tree to tree. They have also witnessed firsthand that a tree infected with oak wilt will die within a matter of weeks because no treatment options are available.
But instead of just wondering whether any trees will survive the disease's relentless march, they plan to take a proactive approach to preserving as many oaks as they can by containing the disease.
"We want to have an evaluation done of our property," said David Fink, who with his wife has been reading up on the oak wilt spread and treatment. "We also plan to have someone come and sever the root grafts."
Severing the root grafts is a technique that begins when a tree care professional evaluates the disease pattern of red oaks in an area. This person decides which trees are already infected or the path of infection and then decides where to cut the mass of roots that connect nearby oak trees to each other. This cut, which should be done by a professional using a five-foot vibratory plow, stops the spread of fungus spores from tree to tree via the roots.
This step is crucial to containment, experts say, because even dead trees can spread the fungus spores for years via the roots. In fact, removing a dead tree within 40 feet of another red oak can spread oak wilt even faster to adjoining trees.
"The fungus will survive in roots for one to three years even in a dead tree," said Jenny Juzwik, the Forest Diseases Project Leader at the North Central Forest Experiment Station in St. Paul, Minnesota. "We recommend proper removal of dead trees, which can mean leaving it for a few years unless zoning laws don't allow that. Some people then treat the stump with chemicals to make it dry up faster and stop the spores."
Juzwik was in Traverse City last week to help evaluate the region's oak trees and document cases of oak wilt. The disease, which is thought to be native to the United States, also affects white oaks, though these trees take years to die.
With pockets of oak wilt already found in Long Lake, Green Lake and East Bay Townships, Holiday Hills and the Forest Lake area over the past decade, she knows first-hand from Minnesota's experience that this is just the beginning.
Juzwik discussed oak wilt prevention and treatment strategies with nearly 40 homeowners, including the Finks, at a meeting last Wednesday evening at the Northwestern Michigan College. She also spoke at a second meeting on Thursday afternoon for arborists, landscape managers, utility company employees and other tree-care professionals. The Grand Traverse County MSU Extension and the Grand Traverse/Leelanau Conservation District, both organizations concerned with the disease's spread, sponsored these meetings.
Juzwik said that one of the most basic things a homeowner or tree care professional can do to prevent oak wilt is not to prune or harvest their oak trees during the spring months. Preventing injuries to the tree during those crucial months of growth helps the tree fight off the disease-bearing beetles.
Because even this basic step is unknown to many homeowners and tree-care professionals, education is crucial to both preventing oak wilt and containing its spread. Organizers held these meetings to begin this educational process that will help save area oak trees.
"The problem with oak wilt early on was that we did not know enough about it, but we've learned a lot since," said Rick Moore of the Grand Traverse/Leelanau Conservation District. "Trees definitely raise property values and quality of life, we need to work together to save them."
Along that line, Juzwik discussed efforts in Minnesota by neighborhoods and communities to band together and combat oak wilt. Juzwik strongly recommended that residents in the Grand Traverse region think of how to work together and begin their own program to save the area's oak trees.
"It is up to you if you have an oak wilt program in your community," Juzwik noted. "You can't do this in a year or two, you have to be committed for at least five years."
"You are protecting trees we couldn't replace in our lifetime."