This fall, forgo the yard clean-up and consider leaving the leaves for the health of your local ecosystem. Fallen leaves return nutrients to the soil, provide insulation for plants, and create important overwintering habitats for a host of wildlife from luna moths and salamanders to even red bats!
Dead Leaves Create Layers of Benefits – Retaining Moisture and Heat and Adding Nutrients
Autumn is an important time to recharge the moisture in the soil that was depleted during the summer growing season. Fallen leaves form a physical barrier to the ground which reduces the amount of moisture leaving the soil, allowing the earth to retain moisture for longer. Water is also an important conductor of heat, and moist soil will do a better job retaining heat close to the surface near plant roots, especially when covered by an insulating layer of leaf litter.
Once on the ground, leaves are slowly broken down by decomposers like millipedes, sowbugs, fungi, and microorganisms who release the stored nutrients back into the soil. These nutrients will be used by nearby plants to promote growth next spring.
Leaves Create Habitat for Wildlife
The layer of insulation from fallen leaves also benefits animals hibernating underground. As the leaf litter deepens to about three inches, it begins to benefit animals that will burrow into the leaves and hibernate, such as wood frogs, box turtles, and red bats. The additional warmth provided by the leaves helps these animals save energy and prevents them from freezing during hibernation as temperatures drop in fall and winter.
Many invertebrates, including fireflies, moths, and butterflies will also overwinter in the leaf litter as eggs, larvae, pupae, or adults so it is important not to shred the leaves. Doing so can disrupt or even destroy these individuals. Shredding the leaves will also decrease their effectiveness in insulating soil.
Impacts to the Land, Water & Air from Leaf Removal
There are also wider environmental benefits to choosing not to remove your leaves. In 2018, the U.S. EPA found that yard debris creates 35 million tons of waste per year for landfills. While the leaves, sticks, and old plant material would decompose into compost in an open-air pile in your yard, in a landfill the yard waste is buried and decomposition occurs in anaerobic conditions (without access to oxygen) which produces methane, a greenhouse gas.
Plant and Wildlife-Friendly Yard Clean-Up
If you choose to tidy your lawn this season, consider landscaping mindfully. Your backyard habitats can benefit from raking fallen leaves into gardens, under trees, or compost piles, which replenishes the soil that sits beneath these areas. Fall is also a great time to plan new gardens for the spring. A thick layer of leaves will smother existing grass and create compost that will be ready for new native plantings in the spring (pro-tip: an added layer of water will hold the leaves in place).
A three- to five-inch-deep layer of leaves will benefit gardens by insulating the roots of perennials, suppressing weeds, and adding nutrients that will eliminate the need for chemical fertilizers. Instead of cutting back dead plants this fall, consider providing habitat for pollinators and other invertebrates to overwinter in flower heads and stems. Goldfinches will feed on the seeds of dead flowers, like coneflowers, all winter long if left standing.
When will you know it is safe to begin landscaping in spring? We recommend waiting until April or May, or when you see bees and other pollinators, before cutting back standing dead vegetation. This allows insects time to emerge from hibernation.
Woody debris can also be stacked to create entire ecosystems for snakes, lizards, and small mammals. These piles will be used during hibernation but also next spring and summer as a place to hide and feed. Add interest to your gardens by placing old logs which will create warm, moist habitats for redback salamanders and American toads.
Now that you no longer have to battle the leaves, you can sit back, enjoy the beautiful fall foliage, and think about all the life living under your leaves!
