St. Charles could replace thousands of trees to prevent emerald ash borer

With an eye toward preventing another emerald ash borer-type tree plague, St. Charles officials are turning their attention to what the next 25 years has in store for the city's 19,000 parkway trees. Plans include the planting and replacement of thousands of trees, a possible discount on utility bills and new tree planting requirements for builders.

Aldermen embraced the details during their first look at the new urban forestry management plan this week. The city's nine-member trees commission spent the past few years drafting the plan.

"The city really helped us a lot to get this done," said Ralph Grathoff, commission chairman. "You kind of have an owner's manual now for all the trees we just bought to replace the (emerald ash borer)."

City workers removed about 4,250 trees the past 10 years due to emerald ash borer infestation. About 245 public trees impacted by the insects remain. Many of them are being treated by private residents. Part of the problem, according to the new plan, is developers constructed many of the city's neighborhoods using the same type of tree to create a uniform aesthetic. In the case of the infected ash trees, it ended up creating a buffet in a nice, convenient line for the emerald ash borer. The city's new plan calls for increased diversity in trees to fend off any future outbreaks.

For example, maple varieties comprise 36 percent of all remaining parkway trees. The plan calls for decreasing that maple population by more than half. In contrast, the number of oak trees would grow by nearly three times what currently exists.

Overall, the plan calls for the removal of about 8,050 trees the next 25 years. At the same time, the city would plant about 9,300 trees. The result will be a much more diverse, but much younger and smaller, tree population by 2040.

The average new parkway tree costs $250 equating to a price tag of about $2 million for the trees the city wants to plant. There are a couple of ideas about how to shrink that cost.

One plan involves the city finding land to create its own tree nursery. The second plan envisions an incentive program for private residents to grow the trees for the city.

In the incentive program, a resident could grow up to three trees for use by the city. The city would repay the resident for each tree grown with a 5 percent reduction in water and sewer bills for the lifetime of the tree. A resident could grow up to three trees for the city for a maximum utility bill deduction of 15 percent.