How To Compost Leaves (3 Ways To Speed Up The Process)


You might have a big pile of leaves left after fall cleanup in your yard.  Although you can use leaves as mulch in a garden, you can also add them to a compost pile.

So, how do you compost leaves?  To compost leaves, add nitrogen-rich material (like grass clippings) to your compost pile. The nitrogen in “green” compost materials balances out the carbon in leaves. In dry weather, you may need to add water to keep the pile wet. Turn the pile often to aerate it and promote faster decomposition.

You might want to wear a mask when working with leaves and compost to avoid breathing in leaf mold (it can make you stuffy if you are allergic).

In this article, we’ll take a closer look at how to compost leaves and what to add to speed up the process.  Then, we’ll answer some common questions about using leaves and compost in the garden.

Let’s get started.

How To Compost Leaves

The first step in composting leaves is to make sure that your source of leaves is safe.  Otherwise, you may end up with “killer compost” that can harm your plants.

Do not use leaves that may be contaminated by pesticides or herbicides (for example, leaves that are mixed in with grass clippings from a lawn treated with weed killer).

leaves
Make sure your leaves are not mixed with grass treated with pesticides or herbicides.

There are several ways to find leaves you can safely use for your compost pile:

  • Leaves from your own yard work
  • Leaves from neighbors, friends, and family
  • Leaves from local landscaping companies (as long as they are not mixed with grass from treated lawns)

Once you have a safe supply of leaves, you can start your compost pile.  Now it is time to find some “greens” to add to your pile.

Add Some Greens To Your Compost Pile

Leaves contain lots of carbon, which makes it a “brown” (carbon-rich) compost material.

Grass clippings, on the other hand, contain lots of nitrogen.  This makes them a “green” (nitrogen-rich) compost material.

cutting grass
Grass clippings are a “green” compost material, since they contain lots of nitrogen. This makes them a good complement to leaves.

You want a good mixture of both green and brown material in your compost pile. That way, the nitrogen and carbon are balanced.

Too much carbon will tie up all of the available nitrogen in the pile (at least temporarily). Too little carbon means the pile will decompose slowly (if it decomposes at all).

Here are some common nitrogen-rich green materials that you can add to the leaves in your compost pile:

  • Grass clippings (make sure they are from an untreated lawn, since herbicides can hurt your plants, and pesticides can hurt bees or other pollinators.)
  • Weeds from your garden (be careful about adding the seeds of weeds to your compost pile – if there are seeds, you could burn the weeds first.)
  • Tea bags
  • Coffee grounds
  • Vegetable and fruit scraps
  • Manure (such as from chickens, cows, or horses.)
  • Seaweed
  • Kelp
kelp
Kelp is one type of algae. You can add it to a compost pile as one of the “green” materials rich in nitrogen.

You can learn more about high-nitrogen sources here.

For more information on composting, check out some of these articles:

Although a compost pile does need water, it is possible to have too much.  To counter this, you can add sawdust, which is very dry and will help to absorb some of the water.

sawdust
You can add a little sawdust to wet compost to soak up water. However, you should also add some “greens” so the nitrogen will balance out the carbon in sawdust.

Remember though: do not to add too much sawdust at one time, since it is very carbon-rich.  As a result, it will tie up nitrogen in soil in the short-term, making it unavailable to plants.

For more information, check out my article on composting sawdust.

How Long Does It Take To Compost Leaves?

According to the University of Illinois Extension, compost will be ready within 3 months.  This assumes that:

  • you have the proper ratio of nitrogen to carbon in the compost pile (green, like grass clippings, to go along with browns, like leaves or sawdust)
  • you maintain the proper moisture level in the compost pile (not too wet, not too dry)
  • you turn the compost pile often to aerate it (to add oxygen that will encourage bacterial growth and activity)
A compost pile with proper moisture, aeration, and the right nitrogen to carbon ratio will be finished within a few months.

Of course, this means that pure leaves by themselves will decompose more slowly, perhaps a year or longer, especially if left alone.

Having lots of earthworms in your garden can also help to speed up the composting process.

earthworm
Earthworms can also help to speed up the composting process in your garden.

For more information, check out this article from the University of Missouri Extension, which has a table with carbon to nitrogen ratios for sawdust and other compost materials.

How To Compost Leaves Faster

You may not want to wait a long time for your leaves to become garden-ready compost.

leaves
If you don’t want to wait a long time for compost, there are ways to speed things up.

Luckily, there are a few actions you can take to speed up the composting process for leaves.  Let’s get into those now.

Add Finished Compost, Animal Manure, Or Topsoil To Your Compost Pile

It is true that a compost pile needs the proper air and moisture levels, along with a good mix of green to brown materials.  However, sometimes compost also needs a “boost” to help get it started on the path to decomposition.

compost bin
Add some finished compost to a pile that is not broken down yet. The beneficial bacteria can help speed things up.

One way to do this is to add materials that already contain lots of the beneficial bacteria that you want.

A few things that already contain bacteria that help to break down compost include:

  • Finished compost – this is compost that has decomposed completely.  It looks and smells like fresh earth.  There is no detectable trace of the materials that the compost was made from.
  • Animal manure – this includes waste from animals (like cows, horses, or chickens) and their bedding (sawdust, wood shavings, straw, or hay).  Animal waste has plenty of nitrogen (you can tell by the smell!)
  • Topsoil – healthy topsoil from your garden contains bacteria that will help to decompose leaves and other materials in a compost pile.  If you are lucky, your topsoil may also have earthworms, which help to break down a compost pile even faster.
manure
Add aged manure to a compost pile to add nitrogen and beneficial bacteria.

Keep Your Compost Pile Moist (But Not Wet!)

A compost pile needs to be wet enough that bacteria can do their work of decomposition.  Compost should not be too dry, and it should not be too wet.

If you find that your compost pile is too dry, add some water with a hose to keep it moist.

hose spray nozzle
Spray your compost pile with a hose if it is too dry.

You can tell that bacteria are not working if the compost pile is cool or warm, rather than hot.  Remember that a compost pile can heat up to a temperature of 140 degrees Fahrenheit (60 degrees Celsius) when the bacteria are really working!

Don’t worry if you add too much water, or if the compost pile gets too wet after a heavy rain.  In that case, simply add some sawdust to help absorb any excess water.

sawdust
Add a little sawdust to compost that is too wet, along with some greens to balance out the carbon.

When you add compost, remember to add enough extra green material (like grass clippings) to offset the extra sawdust you added.  After all, they key is to balance the nitrogen and carbon in the pile!

Aerate Your Compost Pile By Turning It Over

The bacteria in a compost pile need enough air (oxygen) to work properly.  If your pile sits stagnant, it might not get enough air circulation.

You can use a shovel or pitchfork to turn over your compost pile.  This will aerate the compost (you might see steam coming up from the hot compost in the center of the pile if the bacteria are working properly).

pitchfork
Use a pitchfork to turn and aerate a compost pile to provide oxygen for aerobic decomposition.

Turn your compost pile often enough to give proper aeration. Just remember that turning too often may not leave enough time to heat up the pile (which is a sign that the bacteria are working!)

The University of Illinois suggests turning a compost pile every 2 to 4 weeks. When your turn a compost pile, bring the materials from the center to the outside.

compost bins
Turn your compost pile every 2 to 4 weeks to help with aeration and speed up decomposition.

Another option is to use a compost tumbler. This will allow you to protect the pile from getting too wet in the rain.

More importantly, you can turn the tumbler by hand, with no need for a pitchfork or shovel.

The best part is that you can put a wheelbarrow under the tumbler and then empty the finished compost into it for easy transport.

Are Leaves Good For Compost?

Many leaves make a great addition to compost.  As a brown material, they can balance out green materials (such as grass clippings).

According to the Penn State University Extension, a pound of tree leaves contain about twice as many minerals as a pound of manure.

maple leaves on tree
Pound for pound, leaves contain more minerals than manure.

They suggest starting with a 6-inch layer of leaves (you can either shred them with a lawn mower or not).  Shredded leaves will decompose a little faster (as will any material if you cut it into smaller pieces).

To make it easier to move leaves around the yard, you can rake them onto a tarp.  Then, move the tarp close to the compost pile and mix the leaves in.

plastic tarp
Rake leaves onto a tarp to make it easier to move to a compost pile.

Just remember that certain leaves (such as pine or spruce needles) have resins that protect them from decomposition.  These leaves will take a long time to decompose, so exclude them (or put them in another separate long-term compost pile).

pine needles
Pine needles have resins that preserve them and slow down the decomposition process.

Should I Mix Leaves Into My Garden Soil?

You can uses leaves or chopped leaves as mulch on the surface of the soil in your garden.  However, I would compost the leaves first before mixing into the soil.

compost
You can use whole or chopped leaves as mulch over the topsoil in your garden.

The carbon in leaves can temporarily tie up nitrogen in soil as bacteria work to decompose them.  This denies nitrogen to plants, which need it for growth.

Conclusion

Now you have a much better idea of how to compost leaves, which can save you money on fertilizer for your garden.  You also know about what to combine it with for optimal decomposition speed.

I hope you found this article helpful.  If so, please share it with someone who can use the information.

If you want to read some of my most popular posts, check out the “Best of GreenUpSide” page here.  Enjoy!

~Jonathon

jonathon.david.madore

Hi, I'm Jon. Let's solve your gardening problems, spend more time growing, and get the best harvest every year!

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