Mulch is a wonderful product to use in landscaping because it keeps weeds from growing, protects plants from hot or cold temperatures, and looks good. However, some types of mulch also make for breeding grounds for certain insects like ants and termites.
Do ants like mulch? It isn’t so much that they like it or are attracted to mulch. It’s that mulch, especially as it decomposes, makes a good habitat for ants. That is particularly true for carpenter ants who can infest your home.
The article below explains which mulch is the best to deter ants and how to manage mulch to keep insects out.
Why Ants Nest in Mulch?
Ants are different from termites. Termites move to mulch because it’s a food supply. Ants like it because it is moist, has the right temperature, shields the sun, and makes for excellent mounds. It’s like moving into a furnished apartment.
Mulch comes in different forms and some are more prone to house ants than other forms. You can choose much that prevents insects from nesting or perform some regular maintenance that keeps them from surviving in your mulch.
Two Types of Mulch
Mulch has many varieties but it comes in two forms. There is organic and inorganic mulch.
Organic mulch is mulch made from natural things that decompose like leaves, wood chips, straw, hay, and compost. Inorganic mulch is made from man-made elements that don’t decompose like rubber, stone, gravel, volcanic rock, recycled tires, fabric, and plastic.
Bugs will stand a better chance of survival in organic mulch and that is the type of mulch they will seek out. Inorganic mulch is an excellent pest control method because it doesn’t provide food or shelter for insects.
Landscapers advise stone, gravel, or rock for those looking for an inorganic option. Rubber and recycled tire mulch will work but is considered less attractive and tends to get hotter on its surface in the summer.
The Color of Mulch
Studies show that some mulch colors tend to draw more insects while other others repel them. The University of Tennessee did a study in 2000 that compared black and silver reflective mulch. It found that more insects came to the black mulch set around tomato plants than the silver reflective mulch.
Most landscapers advise avoiding dyed mulches because of the impact of some synthetic dyes on the soil. However, it may be worth it to look at the lighter natural mulches to avoid bug issues.
There haven’t been any studies to compare other colors of dyed mulch with back mulch. If the silver reflective mulch can be used as a general rule to discourage ants from nesting, it may be worthy to consider that other lighter colored or reflected mulches could do the same.
Cedar wood has long been known to repel bugs because of its scent so you would think it would also make a good mulch to repel bugs like ants. Landscapers state is the best of the organic mulches for keeping out bugs.
Cedar has natural chemicals like phenols and acids that not only prevent the wood from easily rotting but they repel insects like termites, cockroaches, moths, and even some ants. These chemicals are natural pesticides. Insects die from phenol exposure as it kills them when it enters the bug’s respiratory tract and blood.
Yet, cedar mulch isn’t a safeguard against all ants and bugs. Cedar attracts aphids. These flying, almost transparent insects leave a honeydew scent behind that lures ants. The moist environment encourages ants to hang around, even when using cedar chips.
That is why it’s important to keep your mulch up-to-date and not let it decay too much before replacing it. Decomposing mulch is a haven for ants.
Your best option is to do all you can to make your garden beds ant-resistant.
Making Mulch Ant Resistant
There are things you can do to prevent ants from building their mounds in your mulch. The first consideration is to properly install mulch to prevent bugs.
Landscapers state to only lay about 2 inches of mulch as deep mulch attracts ants and other bugs. Keep the mulch 6 inches away from your home, structure, or trees. Make sure you rake it occasionally, especially after a rain.
Remember, ants love moisture so raking it will air it out and discourage them from living there.
You can use landscape fabric when you first install your mulch. That keeps weeds from growing but also is bug prevention because insects can’t dig into the ground to forage for food or build nests and mounts.
The bulk of an insect’s food is in the dirt. Preventing them from getting to deeper dirt will discourage them from nesting.
Landscape fabric is good whether you use organic or inorganic mulch.
Those that go with an inorganic mulch won’t need to do this type of maintenance but it doesn’t hurt to rake it sometimes to freshen it and keep bugs from getting too comfortable.
An obvious solution is to kill ants you find living in your mulch. Several ways exist to do that. You can boil water and pour it on the mulch and the ant nest.
Mix sugar with boric acid to make a paste and place it near the ant nest and in the mulch. Ants find it a sweet delight so they carry it to the queen, who dies with all the other ants from eating it.
Another mixture is to combine 1/2 teaspoon of liquid dish soap, 1 1/2 teaspoons of vegetable oil, and 1 quart of water. Put into a spray bottle, shake well, and spray on the mulch. This suffocates ants.
Hardware stores also have products that kill ants but they may have a lasting effect on your yard.
It’s always a good idea to get regular yearly pest control treatments for the perimeter of your home to lower the risk of termites, ants, and other bugs. Some companies have repellent disks that go in the ground that protect your home and gardens.
Is there a good mulch that doesn’t attract bugs besides cedar?
Cypress chip or bark is also helpful in repelling bugs like ants. It contains some of the natural chemicals that cedar has, like thujone, and both repel and kill many types of insects.
What types of bugs like mulch?
Mulch can be a home to many types of insects including spiders, sowbugs, millipedes, earwigs, centipedes, ants, and cockroaches.
What are the white bugs in my mulch?
Those are potting soil mites. They are small and may look like small shite dots walking on top of the soil. They love soil so they will head for mulch quickly.
Why can’t you put mulch next to your house?
Landscapers advise you to leave 6 inches between the mulch and your home so you don’t encourage a bug infestation to travel from the mulch to your house.
What kind of ants live in mulch?
While any kind of ant can live in mulch, organic mulch tends to be a favorite of carpenter ants. These are black ants that love wood. Mulch is one of those things that encourages them to move to your property.