Riverwoods’ beautiful trees provide many advantages, including shade and glorious autumn color. But autumn is called “fall” for good reason. What do we do when all those leaves fall to the ground? Here are some alternatives:
Leave them where they fall. This approach is ideal in the woods. It’s the natural process to which trees and other native vegetation have become accustomed over many, many years. The leaves provide necessary organic matter for the soil and serve as an insulating blanket. Leaves also provide a valuable habitat for wildlife.
Use them as mulch. Mulch is a protective blanket that provides nutrients to the soil. Mulching involves cutting or shredding leaves into small pieces, so they fall into the turf grass or other areas instead of resting on top. Leaves are rich in essential nutrients needed for plants, including turf grass. The small, cut leaves in mulch are easier for insects and microbes to consume, hastening fertilization (the transformation of mulch into compost). In addition, as mulch lies on the surface of the soil, it conserves moisture in your lawn or planting area, insulates the ground from heat and cold, and retards weed growth.
Mulching mowers can be very effective, especially when mulching takes place during dry weather. Even a non-mulching mower will work; it just requires more passes over the leaves. Leave your mower set on its normal height. Mow when the leaves are dry. Use a sharp blade. Several passes with the lawn mower may be required.
Studies show that mulching does not adversely affect turf density or increase thatch. In fact, recent studies have shown that turf that receives mulch greens faster in the spring and requires less fertilizer.
If you have too many leaves to mulch them all for your turf grass, mulching your garden is a great way to prepare it for winter. Or store the mulch for later use. Or consider composting or spreading the leaves loosely into the woods.
Don’t pile them too deeply. Don’t make the protective blanket too deep. Mimic nature, and use a depth of up to 2-3 inches. A greater depth risks smothering vegetation. It also may deplete nitrogen in the soil as it decomposes. Trees can be at risk, too. Since tree roots are shallow, and extend at east to the drip line, deep piling leaves (or wood chips, or just about anything else) on top of the roots can smother even a healthy tree.
It is best to cut or shred (i.e., mulch) the leaves first, so they don’t mat and prevent penetration of air and rainwater.
Compost them. This is an excellent approach, if you have the space. Leaf compost consists of leaves that have decomposed. It’s an excellent fertilizer.
You can pile the leaves somewhere to let them magically turn into the perfect soil. But that magic takes a long time to work. A much faster approach is to first mulch the leaves, and then mix them with grass clippings or other green plant material. The green material provides nitrogen and generates heat to accelerate decomposition. (Don’t use garlic mustard or weeds containing weed seed that could sprout when you spread the compost.) If you don’t have green plant material, spreading a cup of high-nitrogen fertilizer into the pile will work. Wet the pile, and let it sit undisturbed for several months. For faster compost, turn the pile every few weeks to aerate it. You can purchase convenient compost containers that allow you to easily turn the compost by simply rotating the container.
Burn them. This is not the best approach. First, read the Village burning ordinance, which restricts the manner and hours of landscape-waste burning. There are penalties for violating the ordinance. Second, contact the fire department. Third, always make sure the fire is attended by someone with a ready source of sufficient water.
Bear in mind that the tiny smoke particles and toxic chemicals generated by burning leaves have been implicated in various serious respiratory problems, especially with children. It is very difficult for the body to expel tiny smoke particles, so they may remain in the lungs indefinitely.
Bag them and toss into the garbage. This is another less-than-ideal approach. In general, the law does not allow landfilling of yard waste because landfill space is so scarce. Your waste hauler may charge extra to take the leaves away because of the expense of disposal.
Most importantly, leaves are a free and a valuable natural resource that you can use on your property to make it healthier and more attractive.