Composting Leaves: How to Break Down Fallen Leaves Fast
Achieving fast decay when composting leaves can be difficult because they take long to break down. These tips from horticultural expert Sarah Jay will help you speed the process.
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Let’s get real for a second. Composting leaves is one of the smartest things you can do for your garden. It’s a great way to mulch, fertilize, and improve your soil, with plenty of different ways to approach it!
If you haven’t started yet or don’t know where to begin, this is for you. Get ready to learn everything you need to know about composting dead leaves so they break down quickly and turn into beautiful, nutrient-rich leaf compost.
Why Should You Compost Leaves?
Leaves are excellent sources of nutrients and minerals. Up to 80% of a tree’s nutrients end up in its leaves. Often referred to as nature’s nutrient recyclers, leaves provide a perfect way to return valuable nutrients to your soil through composting.
They’re also free! If you have trees in your garden, you know that come fall, you’re almost buried in fallen leaves. Take advantage of this free resource to enrich your garden.
If you don’t have trees in your garden, why not ask a neighbor or friend with trees? Many people would happily pass on a few bags of leaves, especially if you help with the collection. You can also check with a local landscaper. Many are willing to donate bags of leaves since it saves them time and money on disposal fees.
Leaves provide a high-carbon source, or ‘browns,’ for your compost. The carbon-to-nitrogen (C/N) ratio of leaves is typically over 30, often around 50. This means they are low in nitrogen, a component that can be harder to find in other composting materials.
Common Problems With Composting Leaves
There are two main challenges you might encounter when composting leaves:
- Leaves take a long time to break down due to their lignin content. Lignin is resistant to decomposition, meaning green leaves can take a year or more to fully break down.
- Leaves tend to mat, especially when unshredded. Matted leaves create an impenetrable barrier to air and water, significantly slowing decomposition. To prevent this, be sure to shred your leaves before composting.
4 Ways to Deal With Leaves In Your Garden
Here are four great ways to make the most of your yard waste in your garden. The best approach for you will depend on the volume of leaves you have, the space available, and how long you’re willing to wait for decomposition.
We’ll start with composting, then explore a few other ways to manage leaves if you’re looking for more options.
Make Compost
Composting leaf matter takes more time, patience, and effort than simply making leaf mold. But if you have the space and time, yard waste leaves can be a great way to make extra compost for your garden.
Note that not all leaves are created equal. Some compost more effectively than others.
The best leaves for composting are those lower in lignin and higher in calcium and nitrogen. These include ash, maple, fruit tree leaves, poplar, and willow. These ‘good’ leaves typically break down in about a year.
Bad leaves are those higher in lignin and lower in nitrogen and calcium. These include beech, oak, holly, and sweet chestnut. Also, avoid using leaves from black walnut and eucalyptus, as these plants contain natural herbicides that can prevent seeds from germinating. Leaves from diseased plants should also be discarded rather than composted.
However, the juglone contained in oak leaves should break down in a few months, so you can safely compost them and use them in your garden after that.
How to Compost Leaves
First, shred or grind the yard waste leaves. This will significantly speed up the decomposition process. If you don’t have a shredder, you can simply use your lawn mower to mow the leaves and collect them.
Alternatively, a garbage can and a string trimmer will work (be sure to wear eye and ear protection). Fill your garbage can approximately three-quarters full with leaves, insert the string trimmer, turn it on, and move it through the layers of leaves.
Leaves are considered ‘browns’ in your compost pile or bin. To balance them, you need to add liberal amounts of ‘green’ materials high in nitrogen, such as grass clippings or kitchen waste. To prevent attracting pests and to speed up decomposition, bokashi composting is a great way to pre-compost food waste. Mix 4 to 5 parts leaves to 1 part green waste.
Adding a compost accelerator, such as green organic waste, to your pile will introduce beneficial microbes to speed up decomposition.
Turn your pile 1 to 2 times a week, adding more green waste (grass clippings, kitchen waste, etc.) as you turn. Turning the pile and introducing oxygen will help it heat up and compost more quickly. Keep the pile moist—it should have the consistency of a damp sponge. Covering it with a plastic sheet will help retain warmth and prevent it from drying out.
If you consistently turn and aerate your pile, you should have high-quality leaf compost by the following spring.
Extra leaves can be stored in sacks next to your compost pile. These can be added throughout the year as brown materials to balance green waste and aerate your compost pile.
Add Directly To Your Garden
The first and easiest option is to add leaves directly to your soil as a top-dressing soil amendment. This helps insulate the soil and plant roots over the winter. Covering bare soil with leaves during winter (such as in unused vegetable gardens) protects it from heavy rains and winds that can cause erosion and leach out important nutrients.
Chop in a layer of bokashi pre-compost or other green waste, such as grass clippings, to enhance decomposition.
Use to Protect Containers
Leaves can also be used to protect containers from harsh winter temperatures. Cluster your containers together and cover with leaves, including the top and sides of the containers.
If your containers are in a windy location, use chicken wire to hold the leaves in place.
Make Leaf Mold
Leaf mold is the soft, cushiony layer found naturally in forests just above the soil. It decomposes slowly, gradually adding nutrients to feed plants and improve soil structure. While not as nutrient-rich as fully composted leaves, it is easier and quicker to make.
Leaf mold makes a useful mulch around the garden and has an impressive ability to retain water. Good-quality topsoil can hold about 60% of its weight in water, while leaf mulch can retain between 300 and 500%. Be mindful of this, as it may provide excess moisture to your plants.
Making Mold From Leaves
Make a large container for your leaves. A circular compost bin made from livestock wire or snow fencing is a cheap and simple option. Add your leaves, dampen them, and you’re done! It’s that simple.
The finished compost should be ready to use by the following spring or summer, though some people choose to store it for several years.
Leaf mold is slightly acidic, so add ground limestone to your compost if your plants are sensitive to acidity.
Frequently Asked Questions
What leaves should not be composted?
Try to avoid leaves that have a higher lignin content. Also, remember that you should wait at least two months before using compost that has juglone-containing leaves. You don’t want to spread herbicide on your crops unintentionally.
What is the fastest way to compost leaves?
Shred them first, and then hot compost them in a compost pile with high nitrogen-containing plants like grasses and coffee grounds. They’ll break down most quickly this way.
How long does it take for leaves to compost?
It takes roughly two to four months for leaves to break down adequately enough in a compost pile or in a pile of their own.
Do leaves need to be shredded for compost?
They don’t have to be, but shredding will speed up the process.
Are rotting leaves good for soil?
Yes. They decompose and feed nutrients to your garden soil, just as they do on the forest floor.
How do you compost large amounts of leaves?
Use the quick leaf compost method we discussed above, adding nitrogenous plant clippings, food scraps, and other kitchen scraps like coffee grounds to the leaf pile. Effectively, you’re making a compost pile.
