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One of five remaining elms at the Civic Center. Photo credit: John Ramos

The Civic Center elms

Dutch elm disease came to the United States from Europe in 1928 and quickly spread, killing American elms by the tens of millions—first on the East Coast, then spreading south and west. By the 1960s, the disease had reached Minnesota. St. Paul’s elms were devastated; Minneapolis managed to save some of theirs with heavy expenditures of money and labor. In 1971, Duluth hired its first forester, as the city prepared for the arrival of Dutch elm. 

The disease came in 1973, with a single infected tree identified on London Road. The following year saw another infected elm, and the year after that brought four more. City crews battled the disease with careful monitoring, aggressive pruning, and prompt removal of diseased elms—the best practices of the day, and measures that may have helped slow its spread, but year by year the casualties mounted, first by dozens, then hundreds, then thousands. By 1994, only 1,600 of the city’s 8,000 boulevard elm trees remained. Today, the city has fewer than 200 elms left, many of them slated for removal.

The technique that proved most successful at saving trees from Dutch elm disease involved injecting a tree with fungicide before it became infected. The fungicide was drawn up through the tree’s vascular system and distributed throughout its branches and leaves. It was an effective treatment in the right conditions, but it was expensive—prohibitively so, according to city officials at the time. Only 20 elms in the city were deemed valuable enough to merit fungicide treatment: the elms at the Civic Center.

The elms at Duluth’s Civic Center were first injected with Arbotect brand fungicide 33 years ago, on Wednesday, August 8, 1984. The Duluth News Tribune ran a picture of the event. The article notes that the cost to treat 20 elms was $3,600 (about $8,400 in today’s dollars, or $420 per tree).

Arbotect is still used to treat elm trees today; the fungicide sells online for $521 a gallon. The treatment is said to last for three years, but there are certain limitations. It only works if a tree is not already infected with Dutch elm disease; if a tree is infected, Arbotect does not work. Moreover, if the roots of an infected tree merge with the roots of a treated tree, the treated tree can get infected. Also, according to one tree expert I spoke with, if a tree is stressed or flagging, the vascular system may not be healthy enough to distribute the fungicide throughout, leaving the tree open to attack.

Having found the date of the Civic Center elms’ first treatment, I wanted to see the record of all the treatments. I put in a data request to the city, and was told that no such record existed. If the elms had survived for 33 years, somebody must have been keeping track of them; the injections had to be repeated every three years to be effective. But nobody I spoke with knew of an official record of treatment. A number of people mentioned that now-retired city forester Kelly Fleissner had ordered treatments for the elms. (Fleissner retired last September, after receiving a diagnosis of Lou Gehrig’s Disease. My efforts to reach him for this article were unsuccessful.) Building and grounds supervisor Dale Sellner told me he had only been dealing with the city’s trees for the past few years and had “no clue” where an official record of treatment might be found.

I turned to another source. According to city invoices, in 2015 the city paid Rick’s Tree Service $5,320 to inject 9 elms at the Civic Center for Dutch elm disease ($591 per tree). This suggested that 11 elms had died at the Civic Center since 1984 and 9 had survived. 

Prior to 2015, Rick’s Tree Service treated the elms in 2010. This indicated a five-year gap in treatment. Arbotect only protected a tree for three years. Thus, based on the invoices, it appeared that the Civic Center elms had gone unprotected for two years.

In 2016, four of the elms were ordered cut down by the city. Sellner told me that it was a safety issue: The trees were structurally unsound, with hollow trunks and weakened limbs, and they presented a hazard to passersby. When I spoke with Rick Hanson, owner of Rick’s Tree Service, he concurred. “The trees we took out down there, they could have killed somebody with the amount of decay in them. That’s basically why we took them down....You know, the older the tree gets, the more hazardous it becomes, and at what point do you choose between saving a tree and saving the people walking around it? Very busy area down there.”

 
All of which sounded prudent and reasonable, but whatever other factors might have been at play, all four trees also had Dutch elm disease. That certainly didn’t help their condition any, and it may have cost the city unnecessary resources. If the trees already had Dutch elm disease at the time of their 2015 injections, the injections would have been useless. Arbotect only protects uninfected trees.

Based on this history, it seems very possible that the remaining five elms at the Civic Center also have Dutch elm disease. If so, they will not be around much longer.

Ash trees on East Second Street. Photo credit: John Ramos

The ash trees

The need for good record-keeping is immediate. The latest invasive threat to the city’s trees is the emerald ash borer (EAB) beetle, first discovered on Park Point in 2015. EAB is 100 percent fatal to all species of ash. When the city lost its elms, it replaced a lot of them with green ash. Today, the city has 2,400 ash trees on the boulevards. All are in jeopardy.

As with Dutch elm disease, there is an injection treatment that protects an ash tree against EAB. It is expensive—according to Sellner, the treatment costs the city about $250-$400 per tree—and must be repeated every two years to be effective. In 2015, believing that EAB would be most likely to enter Duluth by jumping the St. Louis River from Wisconsin, city employees injected 204 ash trees in the Gary neighborhood with TREE-age, an EAB insecticide. In accordance with its EAB Management Plan, adopted last fall by the city council, the city focused its efforts on trees that were 12 inches in diameter and larger; for trees smaller than 12 inches, removing them and replacing them with other species was deemed more cost-effective. The treated trees in Gary are due for another injection this year.

As it turned out, EAB first appeared on Park Point and a year later in Woodland. This year, Sellner told me, the city plans to inject about 80 high-value ash trees in Woodland. This will bring the total number of injected ash in the city to nearly 300. Under the EAB Management Plan, about 900 ash in the city have been identified as candidates for preservation. This translates into a lot of money. Assuming the lower figure of $250 per injection to be correct, treating 900 trees would require a minimum investment of $225,000 every two years. The city is also offering homeowners the opportunity to “adopt” favored ash trees by paying for their injection treatments themselves.

Currently, Duluth has no forester or city gardener. In a city facing many tree-related challenges, this is a problem. With EAB in town, the need to monitor and maintain the city’s trees will only grow. The city currently does keep track of EAB injections—Dale Sellner provided me with a spreadsheet showing the locations, sizes, and treatment dates of all treated trees—but priorities can change and goals can fall by the wayside. However many trees the city ultimately treats, it is important that the treatment schedule be remembered. As the lesson of Dutch elm disease has shown, without accurate record-keeping the city may waste money and needlessly lose trees.  Forgetting the schedule for one year could kill them all. 

Surviving elm in Morgan Park. Photo credit: John Ramos