Mulch has numerous benefits – it can help to retain moisture, reduce weeds, and improve soil quality. Unfortunately, mulch also attracts bugs.
But this isn’t necessarily a bad thing, after all, bugs are a necessary part of the ecosystem.
Most mulch-dwelling bugs are either harmless or beneficial, especially when it comes to decomposition and soil health.
For example, the presence of earthworms in mulch helps to aerate and fertilize the soil, while small beetles are important for breaking down organic matter.
Bugs, in general, are an integral part of decomposing mulch, aerating the soil, and can keep bad pests in check.
However, there are some bugs that can cause problems. These include termites, slugs, mice, and various types of beetles. Having too much of one thing can be a bad thing.
So why are bugs attracted to mulch in the first place?
Why Does Mulch Attract Bugs?
The simple answer is that mulch provides the ideal environment for bugs to live, eat, and breed. It is usually dark and damp and provides plenty of food and shelter from predators and extreme weather.
Additionally, many types of mulch are made from organic materials like wood chips or bark. This makes them particularly attractive to any insect that feeds on wood, such as termites.
Let’s go over the various creepy crawlies that may make their home in your mulch if they are a bad or good thing, and how you can prevent them from becoming a problem.
Super Tips To Ward Off Bugs
In most cases, having bugs in your mulch isn’t a bad thing. However; here are some tips to keep populations in check:
- Keep mulch at least a foot away from your home. This prevents bugs from easily migrating to your home (especially helpful against termites).
- Avoid laying mulch too thick because this can create a more favorable hiding environment for various types of bugs and increase moisture retention.
- Don’t overwater your mulch and ensure that there is proper drainage so there isn’t still water in your garden bed.
- Make sure to aerate the mulch by turning it over periodically to break up any clumping and prevent water logging. This will help keep the moisture levels in check and disturb any nests or breeding grounds.
- There are many natural insecticides you can use that will help deter insects without damaging your plants and soil health.
- Inorganic mulch like rock, plastic, and rubber will not attract bugs as much as organic mulches. This is because they don’t decay over time, so won’t provide a food source or an attractive smell.
- Some organic mulch like cedar and cypress have oils that naturally deter many types of insects.
- Some plants will naturally repel bugs. You can place these on the edge of your garden or throughout the garden. This will keep bugs away from making a home in your mulch.
Note that these tips work well for virtually any bug that is attracted to mulch. Below we have included some more specific information depending on what insect you are dealing with.
Types Of Bugs That May Call Your Mulch Home
Termites
Mulch attracts termites but not as directly as you would think.
Due to their love of wood, termites may eat some of the wood mulch (which is good for decomposition) but they will mainly use mulch as an easy highway to get to where they want to go – your home.
After all, mulch provides a dark, damp, and peaceful surface above the soil, allowing termites to take a break from digging so much.
When it becomes a problem: Termites are only really a problem if the mulch is too close to the wooden structures that make up your home. They may use the mulch to get easy access to wooden floorboards, window frames, posts, and so on. Once there, they can cause considerable damage eating away at the wood.
The Fix: Keep the mulch at least a foot or so away from your house. This will make your house and any other wooden objects mostly inaccessible to termites. Since termites love damp areas, be sure to turn over and rake your mulch to promote oxygen flow and remove stagnant water. Do this, especially to mulch that is close to your home. On top of this, keep gutters clean and unclogged.
Roaches
Mulch also provides a great place for roaches to hide and nest. They love the dark, damp environment and can often find plenty of food amongst the mulch.
When it becomes a problem: Roaches aren’t usually an issue unless they become numerous enough to be an eyesore in your yard and in your home.
The Fix: To deter roaches, keep mulch aerated and remove any build-up of damp areas. Keep your home clean and free of food sources for the roaches such as crumbs or open containers of food.
In addition, you may consider using natural predators like frogs to eat them or use diatomaceous earth (a natural mineral powder) on the mulch. This will help to repel the roaches and keep them away from your home. We advise against using chemical insecticides as these can be harmful to plants and helpful insects.
Also, keep the mulch away from the sides and edges of your home. This will just make it easier for the roaches to make a quick jump over into your house.
Slugs & Snails
Mulch provides an ideal habitat for slugs and snails who will often hide and lay their eggs underneath the mulch.
These creatures are great at decomposing the mulch and providing organic material for plants, but they can quickly become a nuisance when their numbers become too large.
When it becomes a problem: Slugs and snails are not generally seen as bad pests, but they can be if they start to munch on your plants, vegetables, and seedlings.
The Fix: You can use natural barriers like eggshells, salt, and garlic which will deter slugs as the smells and textures will deter them.
Birds, frogs, and beetles are all-natural predators of slugs and snails, so you can allow them to thrive by providing something they love like a garden pond. This will keep the slug population in check.
Lastly, you can simply pile the mulch a little higher than usual around your plants (but not touching) to create an extra barrier from any slugs and snails that may be lurking nearby.
Ants
Ants can be attracted (or should we say drawn) to mulch for several reasons. One reason is honeydew.
Many plants, like those found in your mulched areas, attract small insects known as aphids and scales. These nibble on the plants and secret the honeydew which in turn attracts ants that love sugar-rich foods. You’ll find ants through the mulch as they search for the honeydew in nearby plants.
Another reason for the ant attraction is wood. Carpenter ants love nesting and burrowing through wood, so if you are using a wood-based mulch you can expect the arrival of a carpenter or other wood-loving ants.
When It Becomes A Problem: Ants can disrupt your soil and mulch drainage ability due to the underground tunnels they create. This can cause water to quickly drain from the soil instead of being absorbed, making it more difficult to water effectively. In particular, if you find ants building nests near your plants, it might be time to take some action.
The Fix: You can use natural repellents such as neem oil, citronella, or peppermint oil. Orange oil or peels can also work well. These can be applied to the top of the mulch in areas where there are nests or where you will think there will be nests.
To prevent ants from finding shelter, clear out fallen tree limbs, leaves, and other debris. Keep the grass short and weed-free, and trim any weeds close to your home. When applying mulch around plants, make sure it’s no more than 2 to 3 inches thick to avoid creating a nesting spot for ants.
Spiders
Spiders like mulch for the same reasons as other creatures, mainly for the moisture and protection it provides. Spiders can be beneficial as they eat other insects that might otherwise affect your plants.
If you use wood-based mulches like bark or wood chips, you may notice more spiders because they are especially drawn to the wood dust that is created when the mulch breaks down.
When It Becomes A Problem: Spiders are not really problematic. They definitely benefit your garden by hunting the very same pests that are on this list.
Of course, venomous species can be problematic and you should be cautious of spiders that may bite if they are bothered.
Additionally, if you come across excessive webbing on your plants, it could be a sign of spider mites, which are harmful to gardens and can cause damage to plants.
The Fix: Spiders are technically not insects but are arachnids. Therefore, what works on insects may not work on spiders. Insecticides, for example, will not be as effective against spiders.
Make sure to remove any build-up debris, such as leaves, wood chips, and other materials that might attract spiders. Also, try to keep the mulch layer thin around plants, so spiders can’t hide in the mulch.
To repel spiders, you can create a spray by mixing 10-15 drops of peppermint essential oil with water in a spray bottle and applying it to the mulch where spiders are. Another way to repel spiders is to place cotton balls with a few drops of peppermint oil in strategic locations.
Water and liquid dish soap (with a citrus scent) also work as a repellant. The dish soap disrupts the spider’s egg cycle, and spiders don’t like citrus scents. You can use lemon, lime, or orange-scented soap to keep spiders away.
Cedar mulch is also fantastic for repelling spiders as the smell of cedar can be off-putting to them. As an added bonus, cedar mulch also helps to repel other pests like ants.
Rodents (Rats & Mice)
Although not technically a bug, we thought including rodents on this list would be helpful nonetheless due to how common they are.
Rodents are attracted to mulch because it provides them with food and a comfortable habitat. The smell of mulch, which can contain decaying leaves and organic material, is what draws them in as well as the prospect of a warm and dark hiding place.
Mulches such as straws, wood chips, and leaves offer a favorable environment for mice and other rodents.
When It Becomes A Problem: Rodents can pose multiple problems in your garden. They may feed on your plants and leave their excrement, which can contaminate the soil. In addition, they have been observed gnawing on trees’ bark, which may cause them to die. Furthermore, if they enter your yard, they may quickly find a way into your house.
The Fix: When it comes to rodents, prevention is key. You want to minimize the hiding spots in the mulch as much as possible. Keep mulch layers as thin as possible, and make sure your yard and garden area is as clean and debris free as possible.
Because rodents have a tendency to enter your home, be sure to keep the mulch further away from your house. This is especially during colder months when rodents will want to camp out in your house for warmth.
For a more direct approach, you can apply peppermint oil, vinegar, and cinnamon (and other scents that rodents dislike) around the edges of your garden beds or on the mulch itself. This will give off a scent that mice find unpleasant and may help deter them from getting close. Finally, you can also set up traps around your yard to capture any rodents that have already made their way in.
Mosquitoes
Mosquitoes are attracted to mulch due to its moisture content and the nutrients it offers. In addition, when mulch decays it produces a bit of heat which also serves as an attraction for mosquitoes.
With just enough moisture, mulch can provide an environment for mosquitoes to breed and lay their eggs. You will commonly see mosquitoes in greater numbers after a period of rainfall because they are attracted to moisture.
When It Becomes A Problem: Mosquitoes are a natural element of most gardens and don’t really damage your plants, mulch, or yard. They do, however; can pose health risks through their bites and be an eyesore as well.
The Fix: Since moisture is the primary culprit in attracting mosquitoes, lowering said moisture will do wonders in keeping mosquito populations in check.
Make sure to not overwater your mulch and perform aeration to break up the mulch and any moist patches.
Regular trimming of plants and bushes can help prevent mosquitoes from hiding in tall grass and foliage. Additionally, keeping your gutters clear of standing water eliminates potential breeding grounds for mosquitoes.
Using insect repellents containing natural ingredients such as essential oils and citronella or making a homemade spray with common kitchen ingredients like garlic, onion, vinegar, and lemon juice, can also be effective in warding off mosquitoes.
Planting certain flowers and herbs can also help deter mosquitoes while attracting beneficial insects such as dragonflies which eat mosquitoes. Citronella grass, marigolds, catnip, lavender, basil, rosemary, lemon balm, and peppermint are plants that you can use strategically in your garden to keep mosquitoes away. Installing a bat house on your property can also help control the mosquito population, as bats consume large numbers of them.
Beetles
There are roughly 400,000 known species of beetles, with thousands more still being discovered. Some of the most common types of beetles include ladybugs, weevils, stag beetles, ground beetles, and tiger beetles.
Most beetles are beneficial to your garden and mulch and act as decomposes. They break down the mulch and return nutrients to the soil. Other beetles are pollinators while some hunt pests like aphids or slugs.
Beetles are attracted to mulch because of the nutrients it provides, moisture, shelter, and temperature regulation. These factors make mulch a great place for female beetles to lay their eggs.
When It Becomes A Problem: There are certain species that can wreak havoc on your mulch and plants.
One such species is the Black Vine Weevil. These beetles are small, black, and have a snout-like appendage. The adults feed on the foliage and the larvae feed on the roots of the plants, causing significant damage. Another harmful species is the Japanese beetle. These beetles are metallic blue-green with bronze wings, and they feed on both the leaves and the roots of plants.
Other troublesome species include cucumber beetles, flea beetles, and leaf beetles which either feed on plants or infect them with bacteria and cause a condition known as bacteria wilt.
If you start seeing symptoms of plant damage, inspect the plants for beetles. If they are the culprit, it may be time to take action.
The Fix: Certain types of mulch are less attractive to beetles. For example, cedar mulch has natural oils that repel many insects, including beetles. Rubber mulch, made from recycled tires, doesn’t hold moisture or provide food, making it less appealing to beetles.
Plants like marigolds, chrysanthemums, and rue are known to repel beetles. Plant these around the perimeter of your garden to deter beetles. Additionally, you can spray a mixture of water and mild dish soap on your mulch. This solution is harmless to plants but discourages beetles.
Just like other bugs, you can keep the beetle population in check by turning over your mulch and making sure it’s not piled too high.
Pest Resistant Mulches
There are several mulches that are resistant to many of the bugs we have mentioned.
Cedar Mulch: Cedar mulch is an organic option that contains natural oils and chemicals that many pests find unpleasant.
The aroma of cedar is particularly effective at repelling ants, roaches, and other insects. Its physical characteristic – rough texture – also discourages pests.
Cypress Mulch: Cypress mulch is quite similar to cedar in terms of being resistant to pests. It also has an unpleasant aroma that bugs don’t like and has an uneven texture which makes it difficult for them to burrow or nest.
Both cedar and cypress mulch have a chemical known as thujone which naturally repels many types of insects and bugs in general.
Rubber Mulch: This inorganic mulch doesn’t provide food or suitable habitat for pests, making it an effective deterrent. Its non-porous nature prevents water retention, thus inhibiting the growth of mold and fungi that might attract pests.
Stone or Gravel Mulch: Another inorganic option, stone or gravel mulch makes the environment inhospitable for pests by creating a hard surface that’s difficult for them to traverse or burrow into.
Cocoa Bean Hulls: While this organic mulch has a pleasant smell that humans enjoy, many insects are repelled by it. However, it should be noted that it can be toxic to dogs.
Plastic Mulch: Plastic mulches are effective at repelling pests by blocking their entry into the soil. It is also easy to install and lasts for a long time. Plastic coverings also reflect light which can be disorienting for some types of pests.
Keep in mind that whilst inorganic mulch excels at repelling insects, it doesn’t provide the innate benefits that come with using organic mulch. Namely, the ability to provide nutrients to the soil, and thereby improve the health of your garden.