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What to expect this spring after suburbs' brutal winter

You may harbor residual angst over the long, brutal winter, and with good reason — we had measurable snow just last week, for goodness' sake.

But despite some stubborn spurts of cold, our season of discontent is pretty much in the rearview mirror. So, as we emerge from hibernation and head outdoors, what fallout will we find in nature from all of that extreme cold and heavy snow?

It's probably not as significant as one might fear. Evergreens are scorched, but lawns and other plants should fare pretty well. Japanese beetle grubs may have been zapped, but other insects, not so much.

Birds return because of light conditions, not weather conditions, and plants and insects respond to current soil and air temperatures, said Nan Buckardt, director of environmental education and public affairs for the Lake County Forest Preserve District.

“The memory of the lingering winter is a human thing, not a nature thing,” she said. “Nature acts in the present.”

Insects

Some good but mostly disappointing news for those who had hoped bothersome insects would be absent this season.

Most insect species in Illinois have a range from Atlanta to Canada, says Phil Nixon, extension entomologist at the University of Illinois, so hope that cold weather would reduce their numbers is wishful thinking.

Outdoor insects are well prepared for the cold as they produce ethylene glycol, an ingredient in automobile antifreeze, and other compounds to lower the freezing point of their cells.

“Compared to what they're genetically set to handle, we had a relatively wimpy winter,” Nixon said. We would have to experience a winter colder than what is typical for International Falls, Minn., to see much effect, he said.

Once the warm sun hits the siding, expect those box elder bugs to emerge like nothing happened, Nixon added.

By contrast, some insects are only marginally hardy and their numbers could be reduced. Mimosa webworm and honeylocust plant bug may be on that list, according to Nixon.

And while white grubs that feed on the roots of our lawns probably were ensconced deeply enough in the ground to avoid the freeze, Japanese beetle grubs don't burrow below 11 inches. After three weeks of the deep freeze, those grubs start to die. Nixon expected about two-thirds of the Japanese beetle grubs bit the dust, which is good for trees and shrubs.

Nixon said it is likely about two-thirds of the tree killing emerald ash borers above the snow line were zapped where the temperature reached minus 20 and that it would probably take about two years for their numbers to fully rebound. However, other experts contend it wasn't cold enough, long enough to have an impact. Nixon noted the severe drought of 2012 weakened ash trees and many of them will continue to die without any emerald ash borer attack.

Plants

Evergreens have taken the worst hit, with a significant number showing signs of winter burn.

Since evergreens don't shut down and the roots were unable to provide enough water from the frozen ground, the result has become apparent, according to Doris Taylor, manager of the plant clinic at the Morton Arboretum in Lisle.

“The evergreens are really brown, so we're getting lots of calls,” she said.

But don't be quick to react, Taylor said.

“We're telling people to hold off trimming,” until the new growth starts, she said. Homeowners can scratch the bark of a branch and if there is a whitish or greenish color beneath, it is still alive, she added.

Tim Johnson, director of horticulture at Chicago Botanic Garden, said new buds are a sign the plant is likely to make it. If the whole plant is brown and there are no buds, it's probably dead and time for a new one, he said.

In general, did the cold snowy winter have a big impact on plants? “It depends how they went into winter, how they acclimated,” Taylor said. Was the root system well established? How old was the plant? Was it well watered before winter?

Experts say the snow acted as an insulator.

“The snow cover overall was helpful in protecting gardens,” Johnson said.

But it also acted as a stepladder for rabbits that were able to reach higher on shrubs to eat.

“If all the bark has been chewed off a stem or a branch, it's pretty certain everything above that will die,” Johnson said. If partially chewed, give it time, he suggested.

As for lawns, a fungal disease called snow mold is evidenced by grayish/white matting. The condition is temporary and lawns typically recover on their own or with a little raking and fertilizer.

Experts generally are optimistic about the growing season.

“As far as I can tell, most things are progressing just fine,” Johnson said. “At this point I anticipate all will be well, but it's too early to be certain.”

Wildlife

Prolonged periods of snow cover and thick ice blocked sunlight and limited the production of oxygen resulting in fish kills in hundreds of ponds and shallow lakes throughout the region, according to Mike Adam, senior biologist with the Lake County Health Department.

Trout are the most sensitive, he said, with walleye, largemouth bass and bluegill on the next tier. Fish kills ranged from a couple of dozen to more than 1,000, Adam said. Enough fish usually survive to repopulate in a few years and restocking a pond or lake is needed only in extreme cases.

What about other critters?

“Anything that was able to hide under the snow had a good year — voles and mice,” said Sarah Surroz, conservation and outreach director for Conserve Lake County. While the rodents were happily hidden, the predators that relied on them were not so lucky.

“I know a few people who found dead owls and that's unusual,” she said.

More rodents will be good for other animals, however.

“It might be a banner year for coyote and foxes,” Surroz said. “All things being equal, the prediction is there will be a ton of mice and voles for the coyotes to eat.”

Surroz also said there may not be as many fawns this spring. Deer become fertile only in autumn and when under severe winter stress, females are capable of reabsorbing their fetuses, she said.

And while winter is over, its effects linger as animals wait for new plant growth.

“Depending on the species, these are the toughest weeks of the year,” she said.

The cold winter may have reduced the number of Japanese beetles. Overall, however, experts say this year's brutal winter won't have lingering effects on suburban plants and wildlife. Courtesy of Chicago Botanic Garden
  Coyote should find ample meals because of an abundance of mice and voles. Overall, experts say this year's brutal winter won't have lingering effects on suburban plants and wildlife. Gilbert R. Boucher II/gboucher@dailyherald.com, 2013
  Snow and ice cover resulted in fish kills in many shallow bodies of water. Bob Chwedyk/bchwedyk@dailyherald.com
  Experts say to give evergreens time to see if they recover from winter burn. Evergreens were one of the few tree species significantly harmed by this year's brutal winter. Mick Zawislak/mzawislak@dailyherald.com
  Heavy snow was a nuisance for people like Vernon Hills resident Tom Herrmann, but it provided insulation for plants. Gilbert R. Boucher II/gboucher@dailyherald.com
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