To Leave or Not to Leave

Fall is quickly approaching, leaves are turning the beautiful colors we love to drive around and look at, and the age-old debate arises about whether or not we should clean up the leaves in our yard. You’ve heard it, I’ve heard it — we’ve all probably participated in the conversation — so we want to dive into this conundrum to determine if or when it’s better to leave the leaves.

Tradition has been to clean up the fall leaves in our yard, but why? Is it the negative societal pressure of having a “messy” or “unmanicured” lawn? From a water quality perspective, our organization often advocates for residents in urban areas to clean up leaves that blow into the streets, as significant rain events can cause them to flow directly through municipal stormwater sewers into our water sources or clog storm drains altogether.

Why is that a problem? When leaves decompose in waterways, they consume oxygen and promote the growth of harmful algae, which is detrimental to fish and other aquatic life. When leaves from whole neighborhoods wash into a lake, river, or stream through a storm drain, the volume of organic matter can overwhelm that body of water.

What happens if everyone cleans up all the leaves in their yard? Many living creatures lose access to vital habitat. Fallen leaves serve as homes for insect larvae, butterfly pupae, and small animals like frogs and toads. Leaves also enrich the soil by releasing nutrients as natural fertilizer. So, what is the solution then?

As with most things in life, nothing is black and white, and the answer we are seeking has some nuance. The best fall leaf cleanup depends on your preferences; you can leave some areas untouched to support ecosystems while clearing near storm drains. This balanced approach provides habitat and lawn nutrients, while helping keep lakes, rivers, and streams clear.