Twenty-five years ago, an epidemic of Dutch elm disease swept over Oak Park and River Forest, and the large elm tree in the front yard of Marc Mercado's parents' house at the corner of Forest Avenue and Division Street was no exception. Mercado's father told him: "If this tree goes, we're selling the house."
With treatment the tree survived, the Mercados did not have to sell their house, and today, at its present estimated height of 75 feet and girth of 50 inches, the tree dwarfs the three-story house, which Mercado and his wife have since bought from his parents. At 130, the tree is 50 years older than the Mercado's 80-year-old house.
But to the Mercado's dismay, the tree recently caught a harsher stain of the disease, and this time around, the giant elm wasn't so lucky. Despite the Mercado's efforts to save the tree, it is too infected to survive and will need to be removed within the next month to prevent a spread of the infection.
In 2005, the Village of River Forest has already lost 42 trees due to Dutch elm.
Dutch elm disease has been a problem in the area for many years, said Mike Grandy of the Park District of Oak Park. It is a fungus spread by beetles that bore into a tree's limbs, and can infect any type of elm tree. Once the beetles hit the circulatory area of the tree, the disease begins spreading throughout its entire body.
If the tree is treated with fungicide and the damaged area is removed before the disease spreads to the trunk, then the tree will survive. But if the disease reaches the trunk, the entire tree will eventually be infected and must be cut down to prevent the disease from spreading to other elms.
A dead tree's mulch is even useless if it died from Dutch elm, said Mercado, because the disease can even spread through that.
"It takes so long for a tree to get to that size and only a short time to take it down," said Mercado.
Mark Janopoulos, an arborist with the Village of River Forest, said that when planting new trees the village now alternates elms with other types in the parkway, to prevent future spread of the disease, which also travels through a tree's roots.
"There used to be just blocks of elm trees," said Janopoulos, "and when one tree would get the disease, it would spread like wildfire throughout the town. The elm population dropped to just a few here and there."
Janopoulos said residents should always be looking for signs that their elms might carry Dutch elm because early detection is the key to survival. Around mid-April, he said, if one branch begins to brown, then the tree should be looked at. He also said it's important for residents to familiarize themselves with Dutch elm disease and not be afraid to question experts about their trees.
"If it's caught early enough there is a 50/50 chance of losing the tree," he said.