Composting and Soil Improvement: Adding Fallen Leaves to Compost Piles

The cool weather of autumn brings with it an influx of leaves. Many people ferry away their bags of leaves, not giving them a second thought. But what many see as nuisances are actually a boon for gardeners – soggy, fall leaves are one of the best materials to put in the compost bin. The result is a rich, dark earth that aids in creating a fertile environment for next year’s plants. 

While some prefer to just let leaves lie on the ground, giving the lawn a picturesque look, it’s not the best idea. An overabundance of rotting leaves can smother your lawn, blocking out sunlight and leaving behind bald patches. Instead of throwing your leaves away, a better option is to use them to make compost. 

 

Why Compost Leaves

Leaves on their own create leaf mold, a type of soil conditioner that is primarily broken down by fungal activity, rather than bacterial composting. Leaf mold in itself is full of nutrients that boost microbial activity, improve drainage, and enhance overall soil health – all of which are conducive to growth. When added to compost, it creates a rich, organic matter that many gardeners attest to as being the proverbial “black gold.”

Another benefit of composting your leaves is the reduction of methane gas, a greenhouse gas. Leaves that are picked up by the garbage collection inevitably end up in landfills, releasing methane in the process. 

Ways to Compost Leaves

After you’ve gathered your leaves, use a wheelbarrow to move the leaves to where you’ll be composting them. Using shredded leaves helps expedite the composition process, which can be done so with a mulching lawn mower or leaf shredder, though some don’t bother. To shred leaves, spread a thin layer on the ground (make sure they’re dry) and mow over them until they’re shredded into confetti-like slivers. 

Composting is a multifaceted process that involves multiple factors and approaches. Below are a few ways to help you make use of your stockpile of leaves. 

Bags 

One of the simplest ways to make leaf mold is by using plastic bags. Rather than waiting for the garbage truck to haul away your discarded leaves, this approach allows you to repurpose trash into treasure over the long-run.  

1. Fill a trash bag with leaves. 

2. Sprinkle with water so leaves are damp, encouraging fungi to grow. With scissors or a fork, poke a few small holes in the bottom of the bag to allow for air circulation. 

3. Tie the bag up and store in a shady spot, like a garden shed. Depending on the size and amount of leaves, the decomposition process typically takes 6 – 12 months. 

Hugelkultur Method 

Popular with raised bed gardeners, the hugelkultur method is ideally started in the fall, when the ground is strewn with ample organic material. Basically, you are building a “hill,” or layered, lasagna-like mound of organic material that gradually decomposes into a cost-effective, nutrient-rich soil mixture. 

When adding in plant debris, avoid any that is diseased or has been treated with pesticides. Also avoid any wood that is rot-resistant (Osage Orange, Black Locust, Cedar). 

1. The first layer of a hugelkultur bed is filled with large logs. Fill in the crevices between the logs with wood chips to aid in moisture absorption. 

2. Add lighter materials, such as woodchips, smaller branches, mulch, grass clippings, and leaves.

3. Add top soil and rich compost. 

Compost Bin              

The third method is to add fallen leaves to an already existing compost bin. The ideal compost bin contains a C/N ratio of 30:1. “Green” materials such as fresh grass clippings and food scraps are high in nitrogen; “brown” materials include dry materials such as leaves, straw, and wood chips. Turn your compost pile weekly, adding in leaves gradually to maintain the balance.

If you’re one of those who avoid traditional composting, you can still reduce your leaf pile through worm composting. One way that abridges many of the steps and the hassle of traditional composting is vermicomposting, or composting with worms. These worm composters, intended to be buried inside raised garden beds, are an ideal solution for beginners who seek to create compost efficiently with minimal maintenance. Gone are the days of laboring over reeking compost mounds – you can even compost inside the kitchen with a kitchen composter. 

Using Finished Compost

Your compost should generally be ready by spring, though if the leaves are larger in quantity, the process may take longer. Gradually, the lumpy, ashen detritus will break down into a dark, crumbly material that resembles the rich soil found on the forest floor. The finished compost can be added as an amendment to soil, mulch, or soil conditioner. 

Leave Some for Overwintering Insects

There’s no need to aggressively patrol the lawn for stray leaves. Avoid cleaning up all the leaves for fall; leave some for overwintering insects. Rifling around in the rank debris are a teeming variety of soil organisms that help enhance soil biodiversity.