The relentless advance of the emerald ash borer is hitting hard in Vernon Hills, forcing the village to scramble to find enough suitable replacement trees.
Infected trees are being removed at a brisk clip in the village and it is competing with other communities to find an adequate number and type of trees to plant. That has led to a run on area nurseries, with demand in some cases outpacing supply.
"Everybody needs lots of trees," said David Brown, public works director in Vernon Hills. "A good practice now is to have a more diverse inventory of trees."
Vernon Hills officials on Tuesday, for example, waived the competitive bidding process because the tree stock of certain sizes and species was exhausted at many nurseries in northern Illinois and southeast Wisconsin. The resolution authorizes staff to purchase up to $72,000 in trees from Kendall Hill Nursery in Newark, east of Yorkville.
"We're taking down trees at a rapid rate," Trustee Jim Schultz said. "They're trying to stay ahead of it as best they can."
Last year, crews removed about 200 infected ash trees, according to village arborist Ken Loar. The expectation was that about twice that number would need to be cut down this year. But that estimate is well off the mark and about 550 trees will be removed this spring throughout the village. About 3,500 -- or about one third -- of the 11,000 village-owned trees in the public parkway are ash trees.
"It's every corner of town," Loar said of the ash borer damage. And that might not be all. "I am noticing more and more trees that are infected that are not on that list."
In several weeks, the village will take delivery from Kendall Hill of several species of oak and some maple, hackberry, Kentucky coffeetrees, hornbeams, Japanese tree lilacs, linden, and hybrid elm among others.
"They (Kendall Hill) have everything we need in the sizes we're looking for," Loar said. "Many of the nurseries are being wiped out of all the tree species they're (communities) looking for."
John Carbonaro, a sales rep for Kendall Hill, said in an email that the emerald ash borer has spread "like wildfire" across northern Illinois.
"As a result, we have seen a great jump in interest as well as orders from municipalities," he said. "We have also had municipalities request that we contract grow trees for future orders."
Brown said the term "exponential death curve" is becoming prominent in forestry circles. Emerald ash borer infestation can't be detected for two or more years. Once the tree damage is noticeable, the expectation is most ash trees in a given area will die within three years, Brown said.
The exotic beetle has destroyed millions of ash trees since being discovered in North America in 2002 in southeast Michigan. In Illinois, it was found in June 2006 in a subdivision near Lily Lake in Kane County.
Vernon Hills uses a chemical treatment to prolong the life of some ash trees so the replacement schedule can be spread out over a longer period, he added.
An infested tree will have dead branches or loss of leaves from top to the bottom. Debris on the ground from woodpeckers is another sign.
For now, Vernon Hills officials say they're fortunate to have found enough replacement trees.
"Next year, we might not be so lucky," Loar said.