Can you Compost Old Mulch?

Many landowners want to reuse mulch from their garden beds and it could help restore nutrient rich soil

A layer of fresh mulch can help your garden soil, providing a protective layer that helps to suppress weeds and support growth.

But what happens when your organic mulch has served its purpose and it's starting to thin out and break down? Is there much use in old mulch that's lost it's vigor? 

Yes, there certainly is! Let's go over the basics of mulch and how to property reuse it.

What is mulch?

Mulch is a broad term that covers any type of protective layer that can go over your garden bed. There are organic mulches, including:

• • Wood chips

  • Shredded wood

  • Tree bark

  • Grass clippings

There are also inorganic mulches, such as:

• • Tarps

  • Gravel

  • Sand

  • Landscape fabric

A Woodland Mills wood chipper like the TF810 PRO can be a very useful tool for making mulch, since it can easily chip fresh, green branches with leaves, giving you a pile of fresh wood chips to use in your garden.

What does mulch do?

Mulch offers a protective layer for your garden soil, helping to suppress weeds while aiding the soil moisture and helping to keep a comfortable temperature for plant growth. Organic mulches will also decay over time, adding to the soil base and restoring valuable nutrients.

Adding a few inches of mulch to your garden beds is an easy way to preserve your soil structure and aid the growth of your flower beds.

What happens when mulch ages?

As organic mulch ages it will start to break down. Soft materials like grass clippings will often decay first while harder materials like wood chips will last a bit longer.

Organic matter will eventually become fresh soil, restoring nutrients to your garden bed. As this happens you should consider topping up with a new layer on top of the old mulch.

Can you compost mulch?

Yes. Mulch composts as it degrades, adding nutrients back to the soil in the same way that adding a fresh layer of compost to your garden would.

However if you want to remove your mulch layer from your garden and bring it to your compost bin that would also work.

Can I compost wood chips?

If you own a Woodland Mills wood chipper, using wood chips in your garden can be very useful. If you want to compost your wood chips, just add them to your compost pile and they will break down with everything else, they may just take a bit longer compared to softer materials like shredded wood or leaves.

How does composting work?

Compost bins utilize heat and moisture to break down food scraps and other organic matter until eventually you're left with a nutrient rich soil that you can use in your garden.

Anything you put in will break down over time, so adding old mulch to your compost pile will effectively increase the rate that it decays and contributes back to the soil.

How should I compost old mulch?

If you're planning on composting your used garden mulch here's how you should do it.

Step 1: Remove Your Old Mulch

Use a rake, shovel or garden fork to gently remove the mulch from your garden, being careful not to damage your plants.

You should do this in the fall, after the growing season has ended so that your mulch can compost over the winter. Only do this with natural mulch as inorganic ones like stones or synthetic fabrics won't break down in your compost.

Step 2: Add the Old Mulch to Your Compost Pile

Maybe you have a bin for table scraps, or just a compost pile in the corner of your property. Either way, the pile will insulate the heat and continue to evolve into a rich soil over the winter, so go ahead and add your old mulch to your compost pile. If you mix it in it's more likely to consistently break down over time as opposed to tossing it in a pile on top.

Step 3: Maintain your Compost Throughout the Year

As your compost pile does its job it will leave a rich useful soil at the bottom. Continue feeding your compost pile throughout the year, topping it up with a fresh layer frequently. This will help insulate the rotting compost so it breaks down into fresh, useful soil.

Summary: Here's how to compost old mulch

Mulch can be a useful tool in your compost bin, especially if you have an old organic mulch that will easily break down when added to your compost pile.

What you should do is:

• • Be careful when removing your mulch from your garden

  • Feed your compost pile with fresh materials throughout the year

  • Ensure your compost pile has the proper moisture and heat

  • Remove your compost in the spring/summer and use it to feed your garden