By Jenny C. Kafas, Volunteer to Franklin Township’s Environmental Commission

Fall is perhaps the most beautiful time of year. The summer greenscape is transitioning into a landscape full of color as the leaves change before dropping to the ground. It’s all stunning until you have to spend a dreadful day going outside to rake.

I remember as a kid having my Fall joy interrupted at least once a year (and often more than that) when my parents declared that today is the day we are raking. We spent what felt like hours outside, and by the time we had hit every spot in our yard, not only were we all grumpy, the trees had already dropped a fresh layer of new leaves too. Sound familiar? I have good news, then. What we really need to be doing is leaving our leaves alone. Fallen leaves, also called leaf litter, are great for the health of our soil, watershed, insects, and plants (believe it or not, this includes your lawn) and by raking them away every year we are doing a lot of damage. Why? Let’s dive into it.

You may have noticed an uptick in flooding and drought periods over the past few years. As climate change prevails, what we are experiencing is rain that is more episodic, meaning that we are experiencing high rainfall in short periods of time, and long periods of time with no rain at all. During long stretches of time without rain, soil loses its ability to absorb water. This is especially true for soil that has no plants or plants with shallow roots, such as lawn, growing on it. When rain finally comes, between the soil that has lost the ability to absorb and filter water, and impermeable land such as paved roads and buildings, the rain has nowhere to go but our streets and basements, leaving us flooded with water rich in sediments and other pollutants. Land that has a healthy layer of leaf litter gains some immunity against this. Not only does leaf litter help filter water, it will store the water and allow it to reach the soil slower. This means the soil can stay moist between rainfalls and be able to absorb water the next time it rains. 

In recent decades we have been experiencing a massive insect decline that has had negative effects on both plant and bird populations. One way that you can help insects is by leaving leaf litter on the ground. It provides vital habitat and insulation for many overwintering insects such as bumble bees that burrow close to the soil surface. They are more likely to survive the winter when there is a layer of insulating leaf litter over them. Many butterflies and moths, such as the Eastern Tiger Swallowtail, also camouflage their cocoons to resemble leaf litter and use fallen leaves to hide.

Leaves do have the potential to kill lawn, but this is really only if leaves create a thick mat that smothers your lawn. In other words, if the leaves make it so you can’t see a single blade of grass, then you might want to do something if you want to see your lawn next year. There are two good ways to approach this. One is to go over your leaves with a lawn mower to chop them up and leave room for what’s underneath them to breathe. Another way to deal with this is to move your leaves to somewhere else but still on your property by blowing or raking. For the sake of the ecosystem, it’s important that you keep as many leaves in your yard as you can.

Still have an itch for yard work? We also encourage people to plant native and reduce lawn space where you can to support local biodiversity and a healthy watershed – and this is the ideal time of year to put native seeds in the ground! Many of our native plants require their seeds to undergo a long period of cool weather before they sprout, so sowing them now is perfect for a lush garden this Spring.