Dutch Elm Disease Screws with Grant Park

By Andrew Peerless in News on Aug 15, 2005 1:39PM

When the summer nears its end and Chicagoist sees the leaves begin to change colors, our thoughts turn to fall, to the crunch of multi-colored leaves beneath our feet and the other delights that accompany our favorite season. For the Chicago Park District, however, a recent sighting of yellowing leaves and wilting branches in a Grant Park stand of elms signified just one terrifying thing: Dutch Elm Disease.

We told you all about Dutch Elm Disease when Evanston, hell-bent on combating the disease, started a high-profile tree innoculation program last spring. Now, around 30 of Grant Park's 600+ elms are showing signs of the disease, which is carried by the beetle at right. It kills defenseless trees by inhibiting their water distribution systems and - unfortunately - moves efficiently from tree to tree through interwoven root systems. Large stands of a single type of tree - such as Grant Park's - are especially susceptible to Dutch Elm infestations.

The city is planning to yank the infected trees this week, and a private company will follow up with full-scale excavation of the victims' existing root systems to curb further infestation. The poor departed souls will be replaced with more elms, though a heartier batch bred for its resistance to Dutch Elm Disease, as well as maples and oaks that will hopefully help spread further large-scale epidemics.