Grand Forks Park District, UND tree programs aim to eliminate Dutch elm disease
The Dutch Elm Disease Program with the Park District helps slow the spread of Dutch elm disease and removes infected elm trees free of charge to homeowners.
GRAND FORKS – As June approaches and trees begin to leaf out, Sean Lee, the forestry operations manager with the Grand Forks Park District, knows it’s time to begin watching out for Dutch elm disease.
During the months of June, July and August, scouts with the Grand Forks Park District Forestry Department will survey elm trees on berms, parks, private property and the city river corridor for Dutch elm disease, considered one of the most destructive shade tree diseases in North America.
To help slow its spread, the Park District has a Dutch Elm Disease Program. While Lee said similar programs are offered in other cities across North Dakota that have Forestry Departments, the Dutch Elm Disease Program in Grand Forks is unique — residents don’t have to pay for the diseased tree to be removed on their property. Lee said funds are set aside each year for Dutch elm disease removal to ensure there is no charge to homeowners.
When looking for Dutch elm disease, Lee said scouts have to wait for the trees to be fully leafed. This is because the signs of Dutch elm disease in elm trees is browning at the tip of branches and leaves on the affected branches becoming dry and brittle. When peeling the bark back, infected trees will be stained with light to dark brown streaks.
Lee said Dutch elm disease spreads to other elm trees by beetles.
“If they’re in the tree they can get the disease on them and then when they leave that tree and go to another elm they’ll spread it that way,” Lee said.
Trees also can spread it to nearby trees, through the root system.
In Grand Forks, when a tree is determined to have Dutch elm disease, it is removed as soon as possible to prevent spread. When the diseased elms are cut down, they are taken to the landfill and chipped.
Lee said the number of diseased elm trees removed annually varies. Some years have seen nearly 1,300 trees removed, but that number has since decreased to around 100-200 trees a year.
“It's kind of been staying down in that 100 to 200 range now for quite a while,” Lee said.
According to the Park District the first case of Dutch elm disease in Grand Forks was discovered in 1979, and since then, the Forestry Department has removed more than 9,000 diseased elms. At present, there are about 3,000 elm trees in Grand Forks that the Park District maintains on the berms and in parks.
Along with cutting down diseased elm trees, Lee said the Forestry Department also plants trees that are resistant to Dutch elm disease.
The same goes on UND’s campus, where Jared Johnson, the university arborist, also is set to begin checking trees. Of the roughly 4,500 cataloged trees on the campus, about 15% are American elms.
He checks them by looking for “flagging,” or leaves that have turned yellow when they still should be green. He makes every attempt to save the tree, by removing the branch if necessary, but if he checks under the bark and finds that the tell-tall “pinstripe” marks have progressed too far, he takes the tree down and hauls it to the landfill.
When he replants elm trees, they are of a disease-resistant variety, and include Princeton and prairie expedition elms, along with some Japanese elm trees. In his time at UND, Johnson has planted a few hundred trees of several different varieties.
Johnson came to UND about two and a half years ago, when the university created a dedicated tree program. Since then, the university has twice been awarded Tree Campus Higher Education recognition from the Arbor Day Foundation, for efforts to manage trees on campus.
A lot of work goes into monitoring elm trees.
If he spots a flagging branch he tests it — sometimes requiring a boom truck to get a sample from the top of the tree. If it's positive, he checks to see how far the disease has spread. He’ll make some cuts with a chainsaw, but has to sterilize the blade with rubbing alcohol for the final cut.
That monitoring and testing process played out with a very large elm tree outside of the Hughes Fine Arts Center. Johnson said he wound up only having to take off one large branch, instead of losing an established tree that lends shade and beauty to the area.
In his first year at UND, Johnson said he was very busy removing trees, and not always elms but ash and other varieties. Work put in through the dedicated tree program has considerably slowed the need to cut more trees.
“The first year we were removing 100 trees a year at the (Ray Richards) golf course, and at least 100 a year on campus for two years,” he said. “Now it's very, very few.”