Why Does Topsoil Have Wood Chips in It?

We use soil for so many different uses, including fuel and plant growth, among other things. But do you know what topsoil is made of? Topsoil often contains wood chips and other organic elements to promote healthy plant growth with natural soil additives. So why exactly does topsoil have wood chips in it?

Topsoil has wood chips in it because they can help the soil retain nutrients and essential moisture. Additionally, they often help the soil “breathe” by funneling air through to the subsoil. Wood chips have their pros and cons, but they are usually an excellent addition to any garden.

In the rest of this article, we’ll discuss why topsoil contains wood chips and how long it usually takes for those wood chips to break down. We’ll also review what topsoil is typically made of and the pros and cons of adding wood chip mulch to your garden beds. Finally, we’ll provide you with a step-by-step of how to use them effectively and what alternatives might be available if wood chips don’t work for you.

Wood Chips Are a Soil Amendment

Wood chips work in a similar way to peat moss or bark. They have essential organic properties that produce chemical reactions within the soil, allowing it to retain moisture more effectively and making the surface softer. 

If the surface of your topsoil is soft rather than hard (for example, softer than it would be if you used stones), it is much easier for plant roots to grow and spread beneath the surface of the soil. If the wood chips are spongy enough, it creates the perfect environment for plant growth.

However, the term “wood chips” is rather a misnomer. Wood chips can refer to shaved bark, sawdust, hard wood chippings, and softened wood mulch. Any and all of these things can be excellent additives to your topsoil (depending on what you’re growing, of course), so if you see the term “wood chips” on your newly purchased bag of topsoil, you’ve probably chosen the right thing. 

Wood chips also decompose slowly, allowing the release of essential nutrients into the soil over a more extended period than other soil amendments, such as peat moss, which needs to be replenished every so often. This slow disintegration allows the soil to slowly absorb moisture as needed without any detriment to the plant.

When mixed with clay soils, wood chips become a veritable superpower; many gardeners have attested to this, suggesting that they promote microbial growth within clay soils and encourage worms and other helpful creatures to visit. If your garden soil is quite heavy with clay, you can’t go wrong with a few wood chips in your topsoil.

Another common question about topsoil concerns compacting. Find out if you need to compact your topsoil before seeding or before laying turf.

How Long Does It Take for Wood Chips to Break Down in Soil?

Wood chips will generally decompose over a long period of time if you’ve included them in your topsoil. How long this process of decomposition takes depends on how soft your wood chips are, the weather, and how small the pieces are.

If you’ve got very small, spongy wood chips, they will take around 12 months to decompose fully, creating approximately 2-3 inches (about 5-7 cm) of organic materials.

However, if your wood chips are harder or bigger, you’re looking at slightly less than 2 inches of organic material after 12 months. 

If you want your wood chips to break down faster, it’s best to pulverize them into a mulch. Doing this will spread the chips out more evenly, allowing decomposition to speed up. 

Pros and Cons of Using Wood Chips in Your Topsoil

While wood chips can be an excellent additive to the soil, it also has a few disadvantages. Before deciding to add wood chips, you’ll need to be aware of what you’re trying to grow in the soil. Below we’ll go through some of the pros and cons so that you can make an informed decision:

Pros of Wood Chips

  • Wood chips are very affordable soil amendments. They tend to be very simple and cheap to manufacture, making them relatively inexpensive for consumers. Additionally, they are easily found in nature, so the process of harvesting them doesn’t have any major negative impacts on the environment. 
  • They’re excellent for helping your soil take in more moisture. Soil is generally very good at retaining moisture, especially if it contains lots of natural, organic matter. However, wood chips take in moisture themselves, slowly penetrating the soil with moisture over time. This inevitably means you don’t have to water the area quite as frequently.
  • Wood chips retain heat really well. If you’re trying to protect your soil from the harshness of a cold winter, sprinkling a bit of wood mulch over the top will help to keep some of the heat in. If you live in an area that often experiences very sudden frosts, wood chips provide a natural blanket for your soil. 
  • They are aesthetically pleasing. If you want your soil to thrive while also adding a bit of textural aestheticism to your garden, wood chips will do the job well. They can make your garden look very organized and put together.  

Cons of Wood Chips

  • Wood chips are not meant for certain plants. Since the process of decomposition uses lots of nitrogen, this nitrogen will be removed from the soil. Unless you put a bit of fertilizer with added nitrogen on the soil, you may find your plants suffer for it. 
  • If you apply too many wood chips, you could end up suffocating your soil. Suffocating the soil means your plants won’t survive because your soil isn’t aerated. 
  • Termites love wood chips. Termites go into attack mode when presented with plant roots, and they can stop plant growth altogether. 

As you can see, the benefits of wood chips generally outweigh the disadvantages. However, it depends entirely on your needs and the needs of your plants.

Are Wood Chips Environmentally Friendly?

Wood chips are, for the most part, considered environmentally friendly additives for topsoil. However, this depends primarily on the manufacturing process and whether or not you need to get them shipped to you. 

In general, since wood chips can be recycled into the soil, they’re being used responsibly. 

You can make your own wood chips if you’re concerned about any negative environmental aspects, such as unnecessary transportation. You can scrape some bark off trees in your garden and soak them in water for a few days. This will soften them up enough to make a good mulch for your topsoil. 

How To Use Wood Chips for Topsoil

If your wood chips aren’t already included in your topsoil mixture, you’ll need to incorporate them into the soil yourself. Follow the steps below to add wood chips to your topsoil:

  1. Make sure you weed your soil thoroughly. Pull out all the roots and use a natural weed killer. Any weed roots left over will resprout after you’ve applied your wood chips. 
  2. Water the topsoil and till it with a rake. This will allow some of the moisture to sink towards the subsoil, creating a perfect base for your wood chips.
  3. Spread out the mulch evenly across the soil and mix it into around 3 inches of your topsoil. 

Once this process is finished, you can continue caring for your garden as usual. You shouldn’t need to replenish the wood chips any time soon; just make sure they aren’t attracting any termites or mushrooms within the soil. Additionally, every so often, you’ll need to make sure that no pesky little weeds are poking up through the topsoil. You can do this by mixing up the wood chips and topsoil occasionally. 

Rubber Chips Are a Good Alternative for Wood Chips

If you’re at the point where you’ve decided not to use wood chips in your topsoil, there are a few other alternatives you can use. As long as you’re using an adequate amount of organic matter such as compost or peat moss, you can use something else to add to your topsoil.

Rubber chips are often considered an effective alternative to wood chips. These are traditionally made from the residues of old tires, making them an excellent choice for those interested in maintaining a sustainable garden. 

Rubber chips are relatively inexpensive as well, making them a great choice for those on a budget. Additionally, their weight serves as an excellent block for weeds—so your weeds won’t be able to grow past them. They last a surprisingly long time and won’t need to be replenished too often. 

Final Thoughts

Topsoil contains wood chips because they make an excellent additive for most soils, especially clay soils. They’re environmentally friendly, relatively cheap to manufacture and purchase, and aesthetically pleasing for those who love an organized garden.

If your topsoil doesn’t already contain wood chips, you can add them by mixing them into the top of the soil after watering and weeding it thoroughly. 

You can use rubber chips if you’re looking for a good substitute for wood chips. Rubber chips are a good investment since they last a long time and prevent weeds from appearing.

Alexander Picot

Alexander Picot is the principal creator of TheGrowingLeaf.com, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

Recent Posts