McHenry County towns are collecting fall leaves, but are they better off as mulch?

In McHenry, the city comes by every two weeks from Oct. 2 though Dec. 4, to vacuum away leaves residents raked to the curb.

In Woodstock, residents get two chances over four weeks to get their leaves to the curb for collection. Crystal Lake doesn’t use the curbside vacuuming program. There, residents who want the city to dispose of their leaves must put them in paper landscape waste bags, or in garbage bins marked for yard waste only.

While McHenry County towns are waiting for the leaves to change color and fall to get their collection programs going, naturalists in northern Illinois and McHenry County encourage homeowners to put them to better use.

“Our evidence that we share with the public is that, whenever you can, leave your leaves on the ground, around trees, shrubs and garden beds,” said Spencer Campbell, the Plant Clinic manager at Morton Arboretum in Lisle.

Most people do all of this hard work to collect, bag and throw away leaves, then have them taken away. But leaves are valuable when used properly.”

—  Spencer Campbell, Plant Clinic manager at the Morton Arboretum in Lisle.

Residents can and should remove leaves from their lawns, Campbell said, either by raking, blowing or mulching the leaves on site. “The grass will not do well with a bed of leaves left on it. But you can take a mulching lawnmower over it a few times .... and you can have mulched leaves on your lawn.”

Brenda Dahlfors, a master gardener and master naturalist with the University of Illinois Extension Service’s Lake and McHenry County office, preaches the benefits of leaving leaves where they fall.

“People - I don’t know - is it a habit? They just do what their parents made them do since they were little kids. Leaves in the fall ... I am supposed to rake them up at get rid of them” seems to be the thinking, Dahlfors said.

The research, she said, says differently.

“Leaving the leaves is actually healthier for our insects, birds - for our environment in general,” Dahlfors said.

In lawns, gardens and flower beds, mulched leaves will decompose through the winter and release nitrogen back into the soil while insulating planting roots over winter, making for healthier lawns and plantings the following year, Campbell said.

“Most people do all of this hard work to collect, bag and throw away leaves, then have them taken away. But leaves are valuable when used properly,” he said.

Around shrubs and plants, homeowners can either rake or blow leaves straight into the beds, Campbell said.

“It benefits insects if they are laid intact” and not mulched, he said. Whole leaves decay more slowly and will “fertilize the soil, help with drainage, and with new roots in the spring, they will have an easier time getting established.”

There are two schools of thought on whether to rake whole leaves into plant beds or whether to mulch them first, Dahlfors said. She subscribes to the whole-leaf theory.

Moths and butterflies will overwinter under the leaves. Sometimes a chrysalis looks like a leaf.

“When you shred that stuff, you are shredding them along with leaves,” Dahlfors said.

She also asks those who enjoy gardening in the spring to wait before they start cleaning up the beds. If gardeners wait for five days straight of 50-degree temperatures overnight, the good insects will have come out for the season, she said.

“We spend all summer feeding the birds and building pollinator gardens and growing native plants to support them. Then we destroy the habitat they overwinter in,” she said.

Ultimately, Campbell said, un-raked lawns might look “untidy or not cared for” which is why homeowners want to remove the leaves. He suggested people try composting on site before deciding to rake all their leaves to the curb.

“Once they learn how valuable it is for their gardens, they would be more likely to try it, or experiment with a portion of the yard,” he said.

One public works director said his town tries to encourage mulching and compositing leaves by sharing information via its newsletter, but residents seem to prefer the vacuum programs.

“Most people want the leaves gone, so they would rather rake to the curb,” Woodstock Director of Public Works Brent Aymond said. “The naturalists would prefer you to mulch. It is healthier for the lawn.

“But that is what we hear the most of: ‘When are you coming to get these leaves?’” Aymond said.