The Barrington Hills Observer

Oak leaves on a lawn. | RJ Carlson /Chicago Botanic Garden

By Tim Johnson | Published in the Chicago Tribune

Will it be okay if I leave leaves in my garden beds at home? My work schedule is heavy this fall and I need some time to relax on weekends versus spending hours picking up leaves.

— Alfredo Alvarez, Highwood

My time for gardening at home is very limited, too, so I look for ways to make my gardening time more efficient. I also prefer a more natural look to my garden, which, fortunately, is easier to maintain, so I adjust my maintenance routines accordingly.

Leaves are now falling and starting to pile up in my garden. The usual fall routine for many gardeners is to remove all the leaves and either bag them up or pile them at the curb for transportation to a landscape waste facility, where they are turned into compost. I have left leaves in my garden beds at home for more than 25 years with good results, which saves time on cleanup while benefiting the environment. This also saves money and time as I do not have to purchase mulch for my garden beds. The only exception is when I plant in the fall, in which case I add mulch to help the new plants through their first winter.

In addition, I do not cut back perennials in fall but wait until spring to trim them to about six inches above the ground. The fallen leaves create a natural mulch, which helps suppress weeds and improves the soil with organic matter as they decompose. The perennial foliage and fallen leaves in the beds create a natural look with lots of winter interest, as well as habitat for insects and wildlife. We all need to do more to support pollinators, and we can help by leaving perennial foliage standing through the winter and keeping leaves in our garden beds year-round. Cut perennials back in late spring to six to eight inches above the ground for maximum benefit for insects.

There are several mature oak trees in my garden, so the leaves tend to pile up too deeply here and there in the borders or blow into dense piles that must be reduced to avoid smothering perennials, groundcovers, and bulbs. Excess leaves can be piled in a corner to decompose, creating compost to use for future soil improvement. Removing leaves from the edges of your garden beds will give you a clean boundary between the lawn and the beds, adding a sense of order to the garden’s appearance. You do not need to grind them up to use as mulch — simply let them fall and blow into the beds naturally.

You can use a mulching mower on the lawn to mulch the leaves and grass clippings to save time while returning nutrients to the lawn. I prefer the look of some leaves left on the lawn in fall versus a clean look and have lowered my mower cutting height to about 2 inches. Change the direction of mowing each time you mow. You should be able to easily see the blades of grass after you are finished mowing for the season. A thick layer of leaves covering the grass will likely smother the lawn if left on it over the winter. A medium to dense layer of leaves can damage any areas of the lawn that have been seeded earlier in the fall and are just getting established. You will need to carefully rake or blow some of the leaves off the new grass if the ground is too soft to push a mower over. If the mower leaves ruts as you are mowing, then the area should not be mowed.

For more plant advice, contact the Plant Information Service at the Chicago Botanic Garden at plantinfo@chicagobotanic.org. Tim Johnson is senior director of horticulture at the Chicago Botanic Garden.