Iowa City asks residents to leave the leaves

IOWA CITY — For many of us, raking leaves into piles to haul to the curb for pickup is as much a part of fall as finding our gloves for the first time since March.

But Iowa City is asking residents to consider mulching the fallen leaves into the grass or putting them on garden beds as a shortcut to enriching soil that has less of an environmental impact from transportation emissions and staff time needed to compost leaves at the landfill.

“Taking leaves to a compost facility and making them a nutrient-rich soil amendment involves a lot of resources,” said Jane Wilch, Iowa City recycling coordinator. “If we can get those same benefits by leaving those leaves where they fall, even better.”

Iowa City suggests three ways residents can leave the leaves on site.

By mowing over fallen leaves, it cuts them up into small pieces that can mix in with the blades of grass. As the leaves decompose, the nutrients go back into the soil to improve the lawn for next year, Wilch said. If the leaf cover isn’t thick, you can even leave the leaves intact without mowing.

While some Iowans enjoy raking, others may consider it a chore they feel they have to do before nestling in for the winter.

“Fall can be something we brace ourselves for because of all the yard work,” Wilch said. “If we can combine those efforts (mowing and raking) we're reducing our yard work time.”

When homeowners layer fallen leaves on garden beds they protect the soil from erosion and create habitat for moths, butterflies, bees or fireflies to lay eggs.

Donald Lewis, an emeritus professor and extension entomologist for Iowa State University, told The Gazette earlier this year fireflies spend 11 months of the year in the larva stage, during which time they hide under mulch, leaves or other decaying organic material. There, they eat slugs, snails, earthworms and other arthropods.

If they don’t have that habitat, their numbers will continue to decline, he said.

Iowa City still offers leaf pickup with the leaf vacuum program, which started Monday, or in bags or with yellow-lidded compost bins. The campaign to leave leaves isn’t intended to deter folks who want their leaves hauled away, Wilch said.

“This campaign is meant to offer a few other options from a climate-friendly perspective,” she said.

The campaign came about through the city’s comprehensive planning, which includes a focus on continuous environmental improvement, Wilch said. If there are fewer rounds driven by leaf vacuum trucks and less hauling of compost back to houses in the spring, it saves fuel and there are fewer emissions.

Another goal is to reduce by 10 percent the massive leaf pile at the Iowa City Landfill. The leaves collected every year are kept separate from the general composting site and added gradually to the mix throughout the year, Wilch said.

“There's a system between dry and wet ingredients,” she said. “Leaves are a very dry ingredient. The finished product takes about a year.”

But the leaf pile is so big, the city can’t use it all before the next fall.

Comments: (319) 339-3157; erin.jordan@thegazette.com