Do Fall Leaves Make Good Compost?

Autumn foliage falls in masses as deciduous trees and shrubs prepare for winter. If you live near these trees, your yard is probably full of fallen, dry leaves! An easy way to process them is to make compost. It’s a nutrient and microbe-rich amendment that helps soils and plants thrive.

Autumn is the ideal time to start a compost pile. The leaf litter creates a huge source of raw debris that you can mix with grass clippings, garden waste, or kitchen scraps. Autumn is perfect because piles need consistent moisture, mild temperatures, and sunshine. The season has these traits, making the decomposition process simple and easy.

Leaves make a good addition to compost piles, but you’ll need other debris to balance them out. Gather your waste and get ready to turn it into black, crumbly, humus-rich compost!

Balance Browns and Greens

Good compost has a healthy mix of greens and browns. These two terms represent different types of debris; greens are fleshy, nitrogen-rich organic matter, while browns are dry, carbon-rich materials. A ratio of 30 parts carbon to 1 part nitrogen by weight creates the best final product with little issues. 

Achieve 30:1 carbon-to-nitrogen weight ratios by adding one shovelful of greens and two or three shovelfuls of browns. This ensures a proper balance of both materials so the pile decays without bad smells or attracting pests and rodents. Because fleshy greens weigh more, you’ll need fewer scoops than light, waterless brown materials.

Fall leaves are brown materials—they contain lots of carbon and little nitrogen, among other micronutrients. Brown materials are things like straw, fall debris, and chemical-free paper or cardboard. To balance them in compost, you’ll need some kitchen scraps or grass clippings to mix in. Other green materials include manure, alfalfa meal, and coffee scraps.

Chop Them Up

Autumn weather can be wet, cold, and rainy. These conditions cause excessive wetness in your piles, making them soggy messes. This is worse when leaves are full-size. Their surfaces cling to each other, forming solid masses of decaying debris.

Speed up the decomposition process and prevent clumping by chopping the residues into small pieces before adding them to the piles. The smaller size helps them come into contact with more decaying organisms and worms and prevents clumps from slowing down decomposition.

Some tools help make the chopping process less time-consuming. If you have a lawn, consider scattering the leaves over it and mowing them up with a mulch plug. Your lawn mower chops up the leaves and puts them into a bag, doing most of the work for you! Other ways involve using pruners, rakes, or shovels to break and chop big pieces into smaller ones. 

Compost Has Needs

Once you make a pile some tasks help keep it in tip-top shape. Piles need three things to work: air, water, and a proper balance of browns and greens. Piles may suffer and start smelling rotten without one of these three components! They ensure the microbes, worms, and larvae stay content and work to defeat diseases and weeds. 

For proper water ratios, ensure your piles have 50% moisture. Grab a clump of your compost and squish it—it should feel like a wrung-out sponge. You want it to be moist but not soggy. The decaying organisms appreciate mild ambient temperatures, and they’ll go dormant as hard frosts grow more frequent in winter. Fall has ideal, cool temperatures that allow the microbes to work without drying out or getting too hot.

The final key to success is turning! Turning is a process of rotating composting materials so more air can reach them. A pitchfork is the best tool for this practice, although shovels, rakes, and hoes can work instead. 

Start by stabbing your pile with the tool, then lift and rotate the debris. Go around your pile and do this on every side to ensure you don’t miss any spots. Use a rake at the end to arrange the waste so it makes a neat, tidy pile. Turn daily or every other day for hot compost and once a month or more for cold compost.

Make Leaf Mold Instead

Leaf mold uses a similar process as compost but it’s entirely leaves! It’s the perfect amendment to make in autumn if you lack green waste. Although it requires less inputs than compost, it takes longer to decay fully and most piles won’t be ready until spring. The final product is worth the wait—it’s black, earthy smelling, and full of nutrients for plants.

To make leaf mold, stack a pile of chopped leaves three feet tall and wide. I like adding small twigs into the piles, as they help create structure and facilitate good airflow. They’re rich in carbon, like a leaf, but they can slow down the decomposition process. Only add a few to help separate the moist leaf layers, and avoid overloading the piles with wood.

Manage leaf mold by turning, watering, and feeding your piles as necessary. Leaf mold needs turning once a week or more to help speed up its breakdown. Every time you turn, you introduce waste to new microbes and worms that voraciously feast on it.

Water the piles so they’re 50% moist like a wrung-out sponge. You’ll have ready leaf mold in three months or longer—the more often you turn it the quicker it breaks down. 

How To Use Compost and Leaf Mold

Compost and leaf mold help certain plants more than others, although you can use both on any plant species. Compost has more nitrogen in it, which causes high levels of bacterial activity. Annual and perennial plants with lots of vegetative tissue appreciate nitrogen and bacteria in their soils, making compost an excellent amendment for these species. 

Leaf mold is different; it is made entirely of fallen tree foliage, meaning it has lots of carbon and little nitrogen. Fungi appreciate decaying carbon sources, and they’re more active where it’s present in high amounts. Leaf mold benefits these fungi, and fungi help woody trees, shrubs, and perennials thrive.

Nowadays, soil scientists are uncovering an entire universe underneath the ground. Studies prove the amazing and important qualities of the fungi, bacteria, and archaea that form partnerships with plants. They live below us in silence, playing a secret role in almost every natural process in our environments.

Mycorrhizae form partnerships with plant roots and create an underground fungal network for maintaining forests. They break down nutrients and feed them to plants in exchange for sugars. You can use these natural partnerships to your benefit by adding compost or leaf mold where they benefit your plants most.

Other Ways To Upcycle Fall Debris

If you have too many piles already, you might be wondering if there are any other ways to recycle your fall debris. There are! They’ll decay on their own without any interference as they do in nature. When trees dump their canopies, they drop them onto the forest floor. The thick, decaying layer adds nutrients, microbes, and worms to the soil as it breaks down.

You can simulate this in your garden by leaving the leaves where they fall. If they fall on your lawn, use a lawn mower with a mulch plug to chop them into the soil. If they fall on your plants, rake them over the soil’s surface so they cover plants’ root zones. 

Cover anywhere there is bare soil with leaves before winter. They’ll insulate the ground and decay in spring as warm temperatures arrive. Where winters are mild they’ll decay throughout the cold season and form ready soil by spring. 

Another inventive way to use them is to make art! Dry and press them for beautiful autumn collages, or use them as prints for illustrations. They add a touch of the outdoors to art canvases, bringing a sense of the garden into our precious homes.