Does Mulch Attract Bugs?


If there are bugs living in the mulch around your home or garden, you may be wondering whether mulch attracts bugs.  I was wondering the same thing myself, so I did some research to find out if this is true, and if so, how to prevent it from happening.

So, does mulch attract bugs?  No, mulch itself does not attract bugs.  However, a layer of mulch can create conditions that allow bugs, such as termites, to survive.  Moisture retained by mulch makes it more likely that bugs will stay once they discover a mulched area.  It is also true that certain types of wood mulch will repel termites or provide less nutrition and decrease their ability to survive.

One of the main requirements for bugs to survive is moisture.  Without it, they will soon dry out when exposed to the fresh air.

Mulch can help to retain moisture from watering or rain.  So, be sure to apply a thin layer (2 to 3 inches or less) to avoid retaining too much moisture.  This will help to reduce the chance of a bug infestation in your mulch.

Let’s take a closer look at bugs in mulch, including termites and ants.  Then, we’ll get into what you can do to avoid the problem of bugs in your mulch in the first place.

Does Mulch Attract Bugs?

No, mulch itself does not attract bugs.  However, if bugs make their way into an area with mulch, they may choose to stay if there is enough moisture.  This is especially true for termites, so let’s investigate their habits first.

Does Mulch Attract Termites?

Mulch itself does not attract termites.  It is true that termites feed on wood, but they also need moisture to survive.  This means that a thin layer of dried-out wood chips will not be very attractive to them.

wood chip mulch
A dried-out pile of wood chips (old mulch) may not be very attractive to termites, due to the low moisture content.

According to the University of Illinois Extension, “Termites live in the soil. They need high moisture levels and dry out quickly when exposed to fresh air. They feed on wood and wood products if the moisture level in a particular location remains high for an extended period of time.”

For more information, check out this article on mulch and insects from the University of Illinois Extension.

As termite scouts move around looking for a place to live, they seek out an area with high moisture levels.  Of course, one of the main purposes of mulch is to help retain moisture when it is watered or when it rains.

termites
Termites prefer to live in areas with high moisture, such as in soil underneath a layer of mulch.

If you are mulching and watering an area regularly, the increased moisture makes it more likely that termites will choose to stay in that area.  In fact, your landscaping efforts may be creating the perfect environment for them!

Of course, you may need to keep moisture levels high to keep your plants alive.  In that case, there are some materials that termites won’t find as attractive as others.  For example, termites have a lower survival rate depending on the type of wood you choose for bark mulch.

According to the Iowa State University Extension, “Termites that fed on a steady diet of either eucalyptus, hardwood or pine bark mulch suffered significantly lower survivorship than did termites fed the standard laboratory control diet of white birch.”

For more information, check out this article on mulch and termites from the Iowa State University Extension.

If you want to keep termites away from the mulch near your house, put out some bait!  That is, give them something more attractive to chew on, and put it far away from mulched areas around your house or garden.

For instance, you can put a pile of cardboard outside in an area away from your house, and let the termites get into that.

flat cardboard boxes
Cardboard boxes can be a good distraction for termites, since they provide more nutrition than ordinary wood.

According to the University of Massachusetts at Amherst, “Many wood-based mulches are not attractive to pest insects but are actually insect-repellent (i.e. thujone produced from Thuja spp.). Termites typically prefer higher nutrient woody materials such as cardboard rather than wood chips.”

For more information, check out this article on mulching from the University of Massachusetts at Amherst.

So, it turns out that mulch made from wood chips does not necessarily attract termites.  Any mulch that retains moisture, such as compost or straw, can also create a soil environment that is more hospitable to termites.

However, you can certainly choose other non-organic materials for mulching, which will make it more difficult for termites to survive (more on this later).

Does Mulch Attract Ants?

Mulch itself does not attract ants.  As with termites, the moisture retained by mulch is what will keep ants around once they find a mulched area.

mulch
Carpenter ants create tunnels in larger pieces of dead wood, but they do not eat it for food.

It is true that some mulch is made from wood chips, but carpenter ants do not feed on wood.  Instead, they chew dead wood to create tunnels, allowing them to live and breed.

According to the University of Wisconsin at Madison, “Carpenter ants do not ingest wood as a food source; instead, they chew non-living wood (in trees or landscape timbers, etc.) to excavate galleries in which they live and raise their young.  Since wood mulch is composed of small wooden pieces, it would not serve as a home.”

For more information, check out this article on mulch and trees from the University of Wisconsin at Madison.

As such, carpenter ants are more likely to make their home in your home, by tunneling through wooden boards, beams, or supports.  So, if you have a problem with carpenter ants, don’t throw away all of your mulch.

fire ants
Ants getting into your house to feed on food scraps or wooden beams is a much bigger concern than them getting into your mulch.

Instead, check out my article on how to get rid of ants in your vegetable garden without killing your plants.

How Do I Keep Bugs Out Of My Mulch?

There are a few important steps you can take to keep bugs out of your mulch.  We’ll use one of the key facts we know about bugs (they need moisture to survive!) to help us keep them away.

Rake Away Old Mulch Before Applying New Mulch

Remember that a thick layer of mulch will retain more moisture, in both the mulch itself and the soil below the mulch.  This is true whether the mulch is made from wood chips, bark, straw, compost, or some other inorganic material such as plastic, rubber, or stone.

Before applying new mulch, be sure to rake away the old mulch first.  That way, you can start fresh with new material.  Also, it will be easier to calculate the amount of mulch you will need to cover the area you want to mulch (more on this below).

Apply A Thin Layer Of Mulch

When applying mulch, use a layer that is 2 or 3 inches thick.  Using any more than that can keep the mulch and soil too moist.  This is just too tempting as a new home for bugs.

To find out how much mulch you need, first you should calculate the size of the area (in square feet) that you want to cover.  Do this by multiplying the length by the width.

If you have an irregular area (like an oval), measure the dimensions of a rectangle that would cover the entire oval.  Then, use an area that is slightly smaller than that.

Once you have determined the area, decide on how thick you want the layer of mulch to be.  Remember that your layer of mulch should be 2 to 3 inches at most!  This prevents the mulch and soil from staying too moist, and it makes it easier to remove old mulch and replace it with new mulch in later years.

Then, head on over to this mulch calculator from Lowe’s to see how much mulch you will need to buy.

Do Not Lay Mulch Near The Foundation Of Your House

This is especially true if you are using organic mulch, such as wood chips or compost.  Putting mulch too close to your house makes it much easier for bugs that live there to move in to live with you!

Make sure that you leave a mulch-free space of at least 6 inches around your house to prevent unwelcome guests from taking up residence in your home.

Also, be careful about putting mulch too close to untreated wood or trees.  Termites may decide to take up residence there, or the mulch may retain too much moisture, causing wood to rot and trees to die.

Water Your Mulch Carefully

When watering your plants, be sure to avoid over watering.  Not only will over watering harm or kill your plants, but it will also create a hospitable environment for bugs in the mulch and soil.

garden hose
If you water your mulch too much, it will stay moist and present a perfect habitat for bugs.

For more information, check out my article on over watering your plants.

What Is The Best Mulch To Keep Bugs Away?

Some of the best mulches to keep bugs away are stone, plastic, and rubber.  First of all, these inorganic materials are inedible to bugs.

Second, and more importantly, these materials will retain less water than organic material like wood chips, straw, and compost.  As we learned earlier, maintaining dry conditions is one of the best ways to discourage a bug infestation.

On the other hand, mulches such as wood chips, straw, and compost will retain moisture.  This may encourage bugs to stay once they have found a mulched area in your garden or near your home.

Conclusion

By now, you have a good sense of why mulch does not attract bugs.  You also know what you can do to keep bugs from getting into your house.

I hope you found this article helpful – if so, please share it with someone else who can use the information.  If you have any questions or advice about bugs in mulch, please leave a comment below.

jonathon.david.madore

Hi, I'm Jonathon. I’m the gardening guy (not guru!) who is encouraging everyone to spend more time in the garden. I try to help solve common gardening problems so that you can get the best harvest every year!

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