Can You Compost Garlic? We Know How!

  • By: Sam Richards
  • Date: July 18, 2023
  • Time to read: 9 min.

As our society becomes more aware of its impact on the environment, individuals and communities alike are continually seeking ways to lessen their carbon footprint and contribute positively towards the health of our planet. Composting, a natural process of recycling organic material like leaves, vegetable scraps, and coffee grounds into a rich soil conditioner, is one such method that has gained significant attention in recent years.

The essence of composting is the transformation of waste into a valuable resource – a rich, nutrient-filled material that greatly benefits the soil in your garden. It’s a natural, environmentally-friendly solution for managing waste, which, apart from its eco-friendliness, also enhances the fertility of your soil, reduces the need for chemical fertilizers, and encourages the production of beneficial bacteria and fungi.

However, as straightforward as composting may seem, the question of what can and cannot be composted often arises. This inquiry is particularly relevant when it comes to kitchen scraps, one of the largest contributors to compost piles. Among these food scraps, one item has been a constant topic of discussion due to its unique properties – garlic.

Garlic, a culinary favorite recognized for its strong aroma and pungent flavor, is used worldwide and is a common waste product in many kitchens. The question is – can you compost it? It’s not as simple a question as it may seem, given the unique properties of garlic. This comprehensive guide seeks to address this question, delving into the nature of garlic, its effects on composting, potential issues and solutions, and alternative methods of garlic waste management.

What Is Garlic and Its Unique Properties?

Garlic, botanically known as Allium sativum, is an integral part of the Allium family, which also includes onions, shallots, and leeks. Originating from Central Asia over 7,000 years ago, garlic has woven its way through diverse cultures and civilizations, playing significant roles in culinary practices, medicinal remedies, and even cultural traditions.

A garlic bulb consists of numerous cloves, each encased in a papery skin. While the bulb as a whole is quite firm, individual cloves are soft, almost buttery, with a potent aroma and a flavor profile that can range from mellow and sweet when roasted, to sharp and intense when raw. This multifaceted nature of garlic has made it an indispensable ingredient in various cuisines worldwide.

Beyond its culinary prowess, garlic is known for its unique chemical composition. One of the main components contributing to garlic’s distinctive aroma and taste is a sulfur-containing compound called allicin. Allicin is released when garlic is chopped, crushed, or chewed, and it’s this compound that has been linked to many of garlic’s reported health benefits, including antimicrobial, antifungal, and antioxidant properties.

Garlic’s strong aromatic nature is not just beneficial for our taste buds but also serves as a natural defense mechanism against pests and predators. The robust scent and flavor can deter certain insects and animals, which has led to its usage as a natural pest deterrent in gardening and farming.

However, it’s these same strong compounds that raise questions when it comes to composting garlic. While the composting process generally benefits from the diverse chemical makeup of different materials, the potent nature of garlic’s compounds might impact the delicate balance within a compost heap, thereby warranting a closer look into how to compost garlic effectively and safely.

The Debate: Can Garlic Be Composted?

The composting of garlic is a contentious topic within gardening and composting circles. On the surface, the question seems simple: Can you compost garlic? It’s organic, it’s biodegradable, so the answer should be a straightforward yes. However, delve a bit deeper, and you quickly realize that the situation is far more complex.

The crux of the debate revolves around the very properties that make garlic so valuable. The potent compounds that give garlic its distinctive aroma and taste, while beneficial in many contexts, have raised concerns in the realm of composting. Some gardening enthusiasts argue that these compounds can disrupt the composting process or even harm the microorganisms, including worms, essential for converting organic waste into nutrient-rich compost.

On the other hand, advocates for composting garlic argue that, like any other organic kitchen waste, garlic can and should be composted. They emphasize that the strong compounds in garlic are not innately harmful to the compost pile and can be managed appropriately, just like any other compost material.

The truth lies somewhere between these two perspectives. Garlic can indeed be composted, but due to its unique properties, it requires a certain level of care and consideration to do so effectively and safely. It’s essential to understand the potential issues that may arise and the best practices to mitigate these risks, ensuring a thriving and productive compost pile.

Potential Issues with Composting Garlic

Composting is a complex biological process involving a vast network of microorganisms, bacteria, fungi, and, importantly, worms. All these elements work in harmony to break down organic waste into nutrient-rich compost. However, adding garlic to the mix could disrupt this delicate balance due to its potent compounds and unique properties.

One of the main concerns raised by compost enthusiasts is the potential effect of garlic on worms. Worms play a critical role in the composting process, helping to break down organic matter more quickly and efficiently while also enhancing the compost’s nutrient content with their castings. Given their sensitivity to certain materials and conditions, it’s reasonable to question how garlic, with its strong compounds like allicin, might affect them.

Some research suggests that garlic, particularly in large quantities, could be harmful to worms. The potent compounds may act as a deterrent, driving worms away from the compost pile. In extreme cases, these compounds could even be toxic to the worms. This potential disruption to the worm population could consequently affect the overall health and efficiency of the composting process.

Apart from its potential impact on worms, other concerns surrounding the composting of garlic include:

  1. Disease and pests: Garlic is prone to certain fungal diseases like white rot. If diseased garlic is added to the compost pile, there’s a risk that the disease could persist in the compost and spread to other plants when the compost is used. Moreover, the strong smell of decomposing garlic could potentially attract pests.
  2. Allelopathic properties: Garlic is known to exhibit allelopathic properties – it produces compounds that can inhibit the growth of certain other plants. If these compounds are not fully broken down during the composting process, they could potentially affect the plants where the compost is applied.
  3. Strong smell: While the smell of fresh garlic might be appetizing in a kitchen context, the smell of decomposing garlic can be quite overpowering and unpleasant. In an urban or suburban setting, this could be a cause for concern.

Understanding these potential issues is the first step towards effectively and safely composting garlic. The key lies in applying the right composting techniques to mitigate these risks and maintain a healthy and productive compost pile.

How to Compost Garlic Safely and Effectively

While the unique properties of garlic present some challenges to composting, they should not deter you from composting garlic altogether. With the right strategies and careful management, garlic can be safely composted without harming your compost pile’s health and productivity. Here are some detailed tips and techniques to help you compost garlic effectively:

  1. Small quantities: The first rule to remember when composting garlic is moderation. Rather than adding a large amount of garlic at once, it’s better to add small quantities over time. This prevents the buildup of potent garlic compounds in your compost pile that could harm beneficial organisms, especially worms.
  2. Balance your compost: The health of your compost pile is greatly determined by the balance between “greens” (nitrogen-rich materials) and “browns” (carbon-rich materials). Greens include materials like vegetable scraps and coffee grounds, while browns include items like dried leaves and paper. A healthy compost pile should have a balance of these materials. When adding garlic, make sure to add an appropriate amount of brown material to balance it out. This helps to neutralize the strong compounds in the garlic and facilitate its decomposition.
  3. Turn your compost: Regular turning of your compost pile is beneficial for many reasons. It aerates the pile, ensuring that the composting microorganisms have plenty of oxygen. It also helps to evenly distribute the materials and their associated compounds throughout the pile. When composting garlic, regular turning can help disperse the garlic and its strong compounds, reducing the chance of harmful concentrations developing.
  4. Healthy compost pile: A healthy and active compost pile can break down materials faster and more effectively, including the potent compounds in garlic. To maintain a healthy compost pile, make sure it has a good mix of green and brown materials, is regularly turned, and is kept moist but not waterlogged.
  5. Observe your compost pile: Finally, it’s important to observe your compost pile regularly. Look for signs of distress, such as a dwindling worm population or a lingering strong smell. If you notice any problems, it may be necessary to adjust your composting practices, such as reducing the amount of garlic added or increasing the frequency of turning.

By following these guidelines, you can successfully incorporate garlic into your composting routine, contributing to the creation of rich, nutritious compost for your garden while also reducing kitchen waste.

Other Garlic Waste Management Options

If composting garlic still seems risky, there are other eco-friendly options for managing garlic waste:

  1. Pest control: Garlic’s strong smell can deter certain pests. You can utilize garlic waste in your garden as a natural pest control.
  2. Garlic-infused garden spray: Garlic-infused water can be used as a natural insecticide.
  3. Creative uses: Garlic skin can be used in crafts, while garlic mustard, an invasive plant species, can be cooked and eaten.


Can You Compost Garlic Skin?

Yes, garlic skin can be composted. It breaks down more easily than the garlic clove and poses less risk to compost organisms.

Can You Compost Garlic Mustard?

Yes, you can compost garlic mustard. However, it’s crucial to ensure that the plants have not gone to seed to prevent the spreading of this invasive species.

Can You Compost Food That Has Garlic in It?

Yes, you can compost food that contains garlic. The same principles apply: add it in small quantities and ensure your compost is well-balanced.

Can You Compost Cooked Garlic?

Yes, cooked garlic can be composted. The cooking process breaks down some of the potent compounds, making it less of a risk to composting organisms.

Can You Compost Rotten Garlic?

Yes, you can compost rotten garlic. In fact, it may be safer to compost because the decomposition process has already started, breaking down some of the strong compounds.


The journey of understanding the compostability of garlic is a fascinating one, taking us through the intricacies of garlic’s unique properties and the delicate balance of a compost pile’s ecosystem. While garlic, with its robust aromatic compounds, does pose some challenges for composting, these are not insurmountable.

Understanding the potential issues, such as the effect on worms, the risk of disease, and allelopathic properties, is key to managing garlic’s incorporation into your compost pile. Through moderation, balancing your compost pile, regular turning, and constant observation, these issues can be effectively mitigated.

The prospect of composting garlic also raises the need to evaluate other potential waste management strategies. Worm composting, creating a separate garlic compost pile, or even using garlic waste in other forms such as garden pest deterrents are all viable options that can be considered.

This discussion sheds light on the larger picture of composting as well. It’s a reminder that composting isn’t a one-size-fits-all process, and different organic materials may require different approaches. It’s a process of continual learning, experimentation, and adaptation. However, the end result – reducing waste and creating a nutrient-rich resource for the garden – is undeniably worth the effort.

In conclusion, yes, you can compost garlic, but doing so effectively and safely requires understanding, care, and a bit of finesse. So, the next time you find yourself with leftover garlic, consider composting it – your garden, and the planet, will thank you.

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