Honeywell: To rake or not to rake

Editor’s note: This is the November installment of a monthly column written by the City of DeKalb’s Citizens’ Environmental Commission that focuses on increased awareness of issues such as promoting projects and ordinance changes involved in recycling, reducing energy consumption and planting native habitat.

As the weather turns colder and the leaves turn colors, many of us prepare ourselves for the yearly task of raking our yards and putting the leaves out by the curb.

This is how we prepare our yards for the winter, after all. But is it always the right choice? Are there benefits to keeping leaves on the ground, and do those benefits outweigh those of raking?

One of the main reasons that we rake is for the aesthetics. Yards simply look better when they are raked, and they look messy when they aren’t. A fully raked yard makes the house look tidy and cared for and prevents the occasional uncomfortable conversation with the neighbors.

But there are other benefits as well beyond the fresh air and exercise we get while raking.

Raking leaves removes the dead thatch from our yard, which helps the live grass to grow. Additionally, many types of grass require sunlight, especially in the fall season, as the cooler weather helps revitalize them for the next growing season. Grasses like Kentucky bluegrass, ryegrass, and many fescues (in short, many of the grasses in Illinois lawns) strengthen their root systems in cooler weather. Leaving a thick layer of leaves on top of them can impede this growth.

On the other hand, keeping leaves where they fall also has long term value. One of the primary benefits is that leaves are biodegradable, break down, and add to the soil, naturally fertilizing the grass below. Fallen leaves also provide food and shelter for many insects and some animals.

The National Wildlife Federation calls leaf layers a mini-ecosystem. Slugs, snails, worms, beetles, centipedes, spiders, millipedes and more live in leaf litter, and leaf layers are vital to the health of the soil. Birds raid leaf litter in the following spring to feed their hatchlings, and many butterflies and moths lay eggs in leaf litter for them to hatch in the spring.

Another benefit is a reduction in emissions if you normally use a leaf blower. Leaves dumped in landfills can also create harmful greenhouse gases, including methane, as they decompose.

Raked leaves can cause additional problems if they are left too long on the curb. Strong rains or winds can send leaves into storm drains and cause clogs.

Is there a happy medium? There can be. One of the best solutions that gains the benefits of both raking and not raking leaves is to use the leaves as mulch after they have dried out. Dried leaves make an excellent mulch and may impede weed growth. Mulching with dried leaves allows them to break down much more quickly, returning nitrogen for future growth to the soil. It also helps retain soil moisture.

Similarly, leaves can be collected and composted, although this requires a great deal more dedication and work than simply mulching them.

Ultimately, the decision of whether to rake, mulch, or compost your leaves will depend on your lawn and your situation. Each choice has potential benefits; your situation and your lawn will determine which of these choices works best for you.