How to put your garden to bed this year
With more chill temperatures ahead in the Chicago area, it's time to put your garden to bed for the winter.
Experts say gardeners' fall action items include leaving the leaves, bringing some plants inside and even planning for next year.
Though autumn may seem like the time of year when gardening tasks dwindle, Arlington Heights Garden Club member Pete Landwehr said he's still knee-deep in getting his plants, pots and equipment squared away.
Landwehr, who is also a certified master gardener through Illinois Extension, said dealing with leaves as they fall is one of his priorities right now. That's because the fallen foliage is a "free winter blanket" used to fortify his garden and protect overwintering insects.
"We're mimicking Mother Nature. Mother Nature doesn't bag up all the leaves and put them on the curb for somebody to haul away," Landwehr said. "If you leave them on the ground where they fall, they break down over the wintertime. All the little microorganisms compost the leaf litter and the vegetation and that becomes organic matter, which feeds the soil and also provides shelter for the insects - the eggs, the adults and the larvae."
Insects like butterflies, moths, fireflies and native bees rely on leaf litter and dead plant stalks to hide in or under. Bees in particular will create burrows underground, staying within an inch or two of the surface. The natural layer of leaves that cover the ground is essential for insulating those burrows and keeping the critters alive.
Because typical grass can't handle the dense leaf litter that covers lawns each fall - it smothers and kills the turf plant - Landwehr said the trick is to rake the leaves up and move them to your perennial beds, shrubs and trees. A layer of two to three inches is ideal.
If there's an excess of leaves leftover, you can put them through the mulch mower until you're able to see the green of your lawn - but don't put all the leaves through the mower as insect eggs and larvae will likely end up facing the blades.
Landwehr added that you don't want to move leaves too far from where they've landed, because insects tend to lay their eggs near their host plant so that when they hatch, they're near their food source.
A prime example is the oak tree, which supports hundreds of insect species, particularly caterpillars.
"There's just a real myriad of species, and there's other wildlife, too, that depend on those leaf piles for not only shelter, but food and water," Merleanne Rampale, education director at the Solid Waste Agency of Lake County, said. "Biologist E.O. Wilson says insects are the little things that run the world. If we lose insects, we also cease to exist."
During the dark winter season, gardeners can also take steps to tackle light pollution, which can confuse wildlife and disrupt their natural cycles, Rampale added. Steps include positioning lights as low as possible, aiming them downward and turning garden lights off at night. Choosing low intensity lighting with warmer or duller hues such as solar lighting can also help.
While mulch provides a home for overwintering insects, it also keeps moisture in the ground, feeds the soil and slows down the freezing process.
As for the actual plants, Landwehr recommends leaving perennials, and taking out annuals and any plants that aren't winter hardy.
To figure out which plants won't be able to handle a Chicago winter, gardeners can look into what zones their plant can thrive in. According to the U.S. Department of Agriculture's Plant Hardiness Zone Map, Chicagoland is largely in zones 5a, 5b and 6a.
If a plant is assigned any higher than that, it won't survive the winter outside, in which case it should be brought in, propagated or left outside to die. For non hardy plants that have tender bulbs like caladiums, dahlias and elephant ears, another option is to dig up the roots, clean them, dry them and store them for the wintertime.
Landwehr said the last step for gardeners is properly storing equipment, which includes cleaning out and bringing in clay pots. That's because some pots can break over the winter, especially if they're left outside with soil still in them.
It's never too early to plan for next year, Rampale said. She especially encouraged gardeners to pursue planting natives, which support local biodiversity, soil health and flood mitigation.
"It's a great time to make plans. A lot of the seed catalogs and plant catalogs come in the middle of winter. You can do a little drawing or layout of your yard and see, 'Could I maybe take a little section over here or here and transform it into a native habitat,'" Rampale said. "It's still not too late to make that plan and have that goal and implement it."
• Jenny Whidden, jwhidden@dailyherald.com, is a climate change and environment writer working with the Daily Herald through a partnership with Report For America supported by The Nature Conservancy. To help support her work with a tax-deductible donation, see dailyherald.com/rfa.