Maggots are often associated with death and decay, and their small, squirming, wiggling appearance does little to offset the unpleasant impression they give. So encountering them, especially when that encounter is a completely unexpected surprise, can be off-putting. Unfortunately, one of those places a chance encounter might happen could be in your compost pile. If this happens to you, the first thing to do, or not do rather, is panic. Maggots in your compost are indicative of a few different things, and can be handled in a few different ways. While it is ultimately a matter of personal preference and comfort level, it doesn’t have to be an entirely negative experience. Here’s what the presence of maggots in your compost pile means, and options for how you can handle that presence.

A healthy compost pile avoids getting too wet because it follows the 60/40 rule: 60% brown waste to 40% green waste.

Contents

What are maggots?

“Maggot” is a term that refers to the larval stage of a fly.

“Maggot” is a term that refers to the larvae of some species of flies. The larvae (plural) is the very young stage certain life forms are born into before undergoing a metamorphosis into their adult state. In the case of certain species of flies, which are typically regarded as an undesired nuisance to begin with, encountering the larvae form can be even moreso. The species that produce these “maggots” are typically houseflies, blowflies, and cheese-flies. But, more often than not, with specific regard to a compost pile, the type of larvae you see are those of the black soldier fly (or BSF).

The black soldier fly (Hermetia illucens) originates from South America but can be found all over the world today. Some insects in general and BSF in particular are experiencing some popularity in the areas of agriculture and food technology due to their composting abilities and high-protein quality content. This particular species eats almost any type of organic waste, meaning they can provide much-needed help in the breaking-down process that results in the creation of compost.

The maggots commonly associated with composting are the larvae of black soldier flies, which are not considered pests and do not spread disease.

Because of their beneficial contributions to these areas, their presence is actually desired, so much so that we’re seeing a rise in BSF maggot farming. When they are raised in strictly regulated environments, they can be a beneficial addition to organic gardening. Farmers are starting to utilize them more and more as a means of green manure, giving the soil more nutrient content while it’s being utilized. When growing crops, especially without organic practices, their decomposition can release nitrogen into the soil, which can help the crops.

It’s worth noting that the BSF, though pesky, is not considered an “invasive pest” the way other flies are, and the main reason for this is because they do not spread disease. They are in fact one of the rare species of flies that this can be said about.

What is compost?

“Compost” is a term that refers to the material leftover after organic materials are broken down during decomposition. It is a sought-after soil amendment due to its multitude of health benefits to plant material.

Composting is the term used to describe the process of breaking down organic material, such as food scraps, into compost, which can then be used to improve soil health. The nutrients that bacteria, fungi, and insects release in decomposing organic materials, called humus, are beneficial to the soil. Composting promotes healthy plant growth and minimizes or eliminates the use of chemical fertilizers.

Are flies necessary to the decomposition process?

Decomposition is the process in which living things break down to their last components, such as their cells and tissues. Flies can be an important part of the decomposition process, but are not necessary for it to be successful. BSFs are attracted to the decomposing organic matter – it doesn’t matter that it’s clean waste. While the presence of BSFs could indicate the presence of undesirable and foreign objects, such as animal by-products or feces, further investigation is required because that is not always the case. BSFs are attracted to all decomposing matter, even that which is clean and organic.

Though potentially useful, flies and maggots are not required for successful composting.

Once attracted by the scent of decomposing matter, BSFs arrive and lay eggs on the surface of the compost pile. These flies and their resulting larvae will eat the tissues and cells of the green waste and defecate them back into the surrounding soil. This process, called bioaccumulation, ensures that all nutrients are absorbed by plants. Aeration is also an essential part of the process of decomposition. This process of aeration involves allowing the decomposing material to breathe and circulate air. Maggots are not required for bioaccumulation to occur, as there are other microorganisms in the compost that perform the same function, albeit on a much smaller scale.

Why is my compost pile attracting flies?

There are many ways flies can be attracted to your compost pile, and in some of these situations, the application is not in your control. However, there are other situations in which the way you are managing your compost may be causing you to attract flies.

The most common reason for flies to be attracted to your compost pile is because the pile is uncovered, leaving it and its attractive aromas exposed to anything in the area that responds to such things. If the presence of flies violates your personal preference, move your compost pile to an enclosed area where it can be outfitted with a lid or cover.

If your compost pile is completely uncovered and exposed, the aroma could attract flies.

It could also be too wet. If the compost pile contains a lot of water, the resulting moist, warm environments are like flashing neon welcome signs to flies. To combat this, turn your pile more often, and incorporate more organic brown matter to offset the disproportionate amount of green waste that is breaking down and causing the over-moisturization to occur.

If you have done your research and educated yourself on what materials are appropriate to include in a compost pile, and you have carefully adhered to that, the presence of flies or maggots should alert you to either the possible problems of being uncovered or too wet, both of which are simple to fix.

However, if you did not take the time to gain a full understanding of what materials should and should not be included in your pile, or you have not upheld those requirements, or you have let others contribute to the pile who may lack the education necessary to uphold the rules, it’s possible an item or items made it through that is causing a contamination that is attracting flies.

What to include and what to avoid in your compost pile

The green to brown waste ratio in compost piles is very important. If the balance is off in either direction, the decomposition process will be impeded.

Compost is made of materials that have been broken down by microbes into mulch and humus. It makes soil healthy and improves its ability to hold water, resist erosion, and support plant growth. Not much else is needed to grow healthy plants, which is why real compost is so valuable.

It can also save you money since using less pesticides means fewer chemical costs.

Dead leaves, fallen branches, grass clippings, and kitchen scraps are the main ingredients of compost. But the kitchen scraps must be strictly regulated. It also includes worms and other tiny organisms that improve the soil, add nitrogen to your plants, and break down organic matter into liquid food for each plant root system. Compost should also include decomposing biodegradable materials such as wood shavings or sawdust, which adds humidity.

It is important that the compost contains sufficient water to prevent excessive hot, dry temperatures. Optimum moisture content of a quality compost pile should be at least 30%.

If your compost pile is too wet, adding brown waste like newspaper and cardboard will help. In the distant pass, newspapers would have been frowned upon due to the lead in the ink, but that is no longer the case.

Adding the right ratio of brown and green materials is key to your compost pile’s viability. Most soil is a mixture of browns and greens, but you don’t want it to be too rich. The brown component includes leaves and twigs, and the greens part can include grass clippings, other green plant parts, and the regulated kitchen scraps. You want the ratio of brown to green to be about 60% to 40%.

As a general rule, there are basic building blocks that should be included in every compost pile, and strict “no-nos” that should be avoided at all costs.

Include things like:

Fruit scraps and peels
Vegetable scraps and peels
Coffee grounds and tea bags
Eggshells

Eggshells are a great addition to a homemade compost pile. Rinse them out before adding.

Paper products like paper towels, napkins, newspapers and cardboard
Garden and yard waste

Avoid things like:

Grain products
Cooking oils and butter
Meat products including bones
Dairy products

Meat and dairy products should not be added to compost piles, and may result in having to start your pile over again.

Pet (dog and cat) waste
Diseased plants
Weeds
Compostable cups and lids

If the above items have made their way into your compost pile, you may have to start a new pile from scratch depending on the degree of breakdown and how long it’s been in there. Grain products and cups or lids that have not been in your pile too long and can be easily removed are not so harmful to the pile that you must start over. But if any other items made it in, the safe bet is to reduce the risk of contamination to your plants and start all over. This may not be an ideal scenario, but remember, you’re making food to feed your plants. If the food you’re giving your plants is contaminated or contains ingredients not in your plants best interest, then they are better off without it.

What about worms? Are they the same as maggots?

Earthworms, incredibly beneficial to soil and plants, are not the same as maggots or flies.

Maggots (which are flies) and worms are not the same thing. They are not the same animal and do not even come from the same phylum. Earthworms are unquestionably very beneficial for the environment. They help break down organic material into nutrients that are used by plants. As worms move around in the soil, they carry nutrients and break down dead plant and animal matter. This means less unwanted material is going to float around on the surface. Worms also help the plants by spreading their rhizomes, stems, and roots. Because of their hard work, earthworms can be beneficial to both plants and humans.

So, are maggots in compost bad?

Regardless of anything else, it is ultimately your garden, and the decision to prevent or eradicate maggots is yours and yours alone. If you’ve decided maggots are not for you, there are measures you can take to prevent and kill them.

After all that, there is no right or wrong answer to this question (as long as their presence does not mean the presence of something harmful to your plants). It depends on your individual garden and composting habits. What the information presented so far should do is arm you with the knowledge you need to comfortably make the determination for yourself. Some people believe that maggots are good in compost because they help break down the decomposing material. Others believe that they’re bad because of what they represent. How you view maggots very much depends on your personal experience and preference.

If you’ve decided maggots are not for you and not what you want in your compost, there are measures you can take to control an infestation once it has occurred, and prevent infestations altogether.

Maggot control measures

There are many effective and natural ways to control the presence of fly infestations in a home garden. If you’re struggling to keep flies away from your compost pile, and have decided their presence is not for you, try the following:

Bio-control by means of beneficial insects. This is one of the most effective ways to control the presence of fly infestations in a home garden. Beneficial insects are natural predators that feed on pest insects, and they can be used to control fly populations without the use of harmful pesticides. There are a number of species of beneficial insects that feed on fly larvae, and they can be introduced to your compost pile to control the presence of flies. For example, you can add small handfuls of aged compost to your compost pile periodically, and place a few combs with holes in the compost for beneficials to breed in.
Suppression via plant selection. It is also possible to suppress fly populations in a home garden by using the right plants and growing them in the right way. For example, you can grow carrots, parsnips, onions, and leeks in pots or tubs to control the presence of flies. The onion family is a natural predator of fly larvae, and their presence in your garden helps to suppress the presence of flies in your compost. You can also grow garlic and marigolds in your garden to suppress the presence of flies. You can add a clove of garlic to your compost pile once or twice a week, and leave a clove of garlic plant near the compost each spring. Marigolds are another great way to suppress the presence of flies in a home garden, as the flowers are a natural predator of the insects.

Garlic is an effective and natural deterrent to fly infestations in your garden, as the smell is a repellant.

Soil inoculation with bacteria or fungi is another way to control the presence of flies in a home garden. You can add a handful of aged compost to the soil in a small container each spring, and place a paper bag over the container to keep out flies. The compost will inoculate the soil with beneficial bacteria and fungi, which will help to control the presence of flies in the garden. You can purchase beneficial bacteria and fungi in pet stores or online, and add a small amount to the soil in a container each spring for effective fly control.

Mixed-plaster fly trap baits are a great way to control the presence of flies in a home garden, as the traps are a natural preventer of the insects. You simply mix POP in water and place the solution in a shallow container, and then place the fly traps near your compost pile for effective fly control. The plaster fly traps work by drowning the flies, which are attracted to the smell of the plaster, and they can be used in any size container to control the presence of flies. Mixing a little bicarbonate of soda or washing soda in water is a great way to make plaster of Paris, and the solution is effective fly control in a garden.

Make or buy a lid or cover for your pile. There are a number of different types of compost lids and covers available online, and they can be used to control the presence of flies in a home garden. Compost lids can be made from materials such as metal, wood, and plastic, and the lid can be placed on a compost pile to keep flies out. You can also place a compost lid under a compost pile to suppress fly populations and prevent infestations from the ground up.

Build a compost pile enclosure. Another great way to control the presence of flies in a compost pile is by enclosing the compost pile. Compost pile enclosures are available in a range of materials, and they can be used to create a sealed compost pile that is insect-proof. You can purchase a compost enclosure online or from a garden center and the compost enclosure will keep out insects, which are attracted to the smell of the compost, and they can be used in any size pile to control the presence of flies.

A compost enclosure not only keeps your compost pile organized and contained, it keeps pests and scavengers away. Composting requires a delicate balance and the less that balance is upset, the better.

Horizontal soil barriers (for example concrete slabs) can effectively control the presence of flies in a home garden. You can create a horizontal soil barrier by placing a concrete slab near the edge of your garden, and then layering soil on top of the concrete. The horizontal soil barrier will create a barrier that is difficult for flies to cross, which will reduce the number of flies in your home garden. You can purchase a ready-made horizontal soil barrier online or from a garden center, or you can create your own horizontal soil barrier using a concrete slab.

Turning your compost pile regularly helps to reduce the presence of flies in your home garden, as the turning process exposes the pile to fresh air and sunshine, which are both factors that attract flies. Turning your compost pile regularly also adds oxygen to the pile, which helps to break down the organic matter in the compost, which reduces the smell and presence of flies in the compost. You can turn your compost pile once a week in the spring and once a week in the fall to control the presence of flies in your compost. The process is easy – just turn the compost with a garden fork.

Keeping your compost pile turned with a simple garden fork is a good way to reduce flies. Regular turning ensures dark, moist pockets are broken up while giving you an opportunity to see if water needs to be reduced or brown waste needs to be increased.

Reduce the amount of water added because the amount of water used to keep your compost pile moist is a major factor in the amount of flies in your compost. Less water/moisture equals less flies.
Add more brown waste such as newspaper, untreated cardboard, coffee grounds, and paper towels into your compost pile to help reduce the presence of flies in your compost. The process is easy – just add brown waste to your compost pile and then turn the compost every week.
Let the pile dry out. If your compost pile is way too wet, it may need some time on its own to dry out in the sun. Refrain from adding more moisture or green waste, leave the pile exposed to the sun, continue turning in brown waste, and allow it to dry out. For very large piles, you may need to spread the material out horizontally so that the shallower depths allow for faster and more-thorough drying out. Once the material is dry, the maggots will die, the flies will leave, and you can start again with adding green waste and water in minimal amounts.

Proper ecosystem management

You’d be surprised at the activity occurring underneath the surface of the ground. Healthy compost and soil are homes to complex networks of microbial ecosystems that form symbiotic relationships with plants and root systems. It’s a delicate balance that should be protected and preserved at all costs.

Keep in mind that a pile of compost is essentially an ecosystem, and that how you manage it is going to make all the difference. For example, if your pile becomes too hot (say, over 140 degrees), then the bacteria will kill off the good organisms, and everything may die-off. But as long as you keep your pile in check, including addressing the conditions which are causing your problem with maggots, you should be able to do just fine. The more you educate yourself ahead of time, the better you are setting yourself up to prevent serious issues, or react to them too late.

Maria P.