Life in Fallen Leaves

With what seems to have happened overnight, the leaves have danced, twirled, and dropped to the ground. The stunning mirage of colorful leaves makes their descent with the coming of a new season: winter. As our yards become decorated with piles of scattered foliage, so too begins the duty of collecting these remains. The usual custom, whether enforced by neighborhood or city rules, or to maintain a clean and aesthetic lawn, is to rake these leaves into piles and consequently transfer them into large trash bags, left by the curb for pickup. In doing this, however, we miss out on a gold mine of organic matter, naturally given to us with each fall season. We also take away habitat for overwintering organisms. Moths and butterflies spend the winter in the fallen leaf layer sheltering in the warmth, or surviving as eggs, caterpillars, chrysalises, or cocoons. Bumblebee queens are known to nestle into the top layer of the soil, using the leaves as insulation to survive cold temperatures; in the spring, they wake up from a state of hibernation and emerge with a mission to start a new colony ready to pollinate the blooming flowers. Indiana is home to several species of salamander that typically forage and hide in fallen leaves year-round. Frogs, toads, turtles, and snakes use the leaf layer as a hunting ground, as well as to escape the cold.

Though we may look at the leaves fallen from the trees in our yards as litter to be bagged and discarded, it is a critical winter habitat for many creatures. This layer is alive. 

What To Do with the Fallen Leaf Layer

Now there is the question of what to do with fallen leaves. The first option is simple: nothing. Leave it! Creatures can take advantage of this natural insulating blanket as the temperatures drop. However, if your trees tend to drop a thick carpet of leaves in your yard, it is important to scatter them into a lighter covering to still allow oxygen and sunlight to reach your lawn. This leads us to the second and third options for using your leaves. You can rake them into piles at the base of your trees, or place a light layer of leaves in your garden beds, making sure to keep a few inches’ distance from the trunk or base to prevent rot. This suppresses weeds, insulates roots, and locks in soil moisture. It also acts as a free fertilizer, as the eventual breakdown of the leaves via microorganisms, fungi, and detritivores helps return nutrients to the soil. Additionally, you can pile leaves in the corners of your yard or along fence lines as intentional, undisturbed micro-habitats. If you are familiar with the concept of a bug hotel, or a bug snug, this is a similar concept, solely with the use of the leaf layer!

While moving leaves, it is important to remember that the leaf layer is alive. Do your best to keep the leaves intact. This means avoiding mulching or shredding the leaves into pieces; we want to protect the cocoons nestled within! Use a rake or a gentle leaf blower to move the leaves where you want them.

Wait For Spring

Because the purpose of leaving our leaves is to allow creatures their overwinter habitat, we may still see partially decomposed or even full leaves in the spring, depending on the conditions of our garden. It is important to allow for the hibernating or cocooned creatures to make their exit before springing into action. Once soil temperatures and outdoor temperatures reach a consistent 50 degrees Fahrenheit, you can start your spring management. It is still recommended to leave as many leaves as you can, as they will continue to decompose and benefit your soil. You may also prefer to redistribute them around your yard, or start a compost pile. Find what works for you—experiment with different options, while keeping conservation in mind!

Written by Alison Isbell

Public Relations and Communications Intern at IWF