CHICAGO — Arborist and “tree doctor” Craig Casino spends his days making house calls and checking on his patients, just like an M.D. This year, his patients aren’t looking very well.
In 40 years of tree care, Casino said, he has never seen weather conditions more devastating than in 2012. Three wetter-than-average summers in 2009, 2010 and 2011 reduced tree roots’ oxygen and water storage capacity, he said. Then, the struggling trees were hit by one of the state’s worst droughts in history, compounding the stress on their root systems.
While memories of the drought might be fading as moisture and cooler temperatures settle in, its impact on trees could play out for years to come. Most immediately the drought may dull the bright leafy reds, oranges and yellows normally expected as the season changes.
“Fall color won’t be as vibrant or as sharp this year,” Casino said. “The trees are changing about four to five weeks earlier this year. The lack of water left them stressed, and now they want to go to sleep.”
Browning, wilting leaves or dropping foliage are signs a tree went dormant in an effort to conserve resources and protect itself, said University of Illinois Extension forestry specialist Jay Hayek.
Trees that didn’t drop their leaves early will still likely display effects of the drought, Hayek said. A lack of water affects the amount of carbohydrates, or sugar, a tree can produce, which in turn affects leaf pigment.
“This year’s fall color will be more drab than years past,” Hayek said.
Hayek said shallow-rooted tree species, such as any variation of Maple, were among of the hardest hit.
The U.S. Drought monitor’s most recent update shows the entire state still under varying drought conditions, though less severe than during summer months. About 40 percent of the state is still in a “severe” drought, according to the map.