Last Modified: April 1, 2024

Cocoa Shells

A Naturally Powerful Weed and Pest Deterrent

Close up of cocoa shell mulch

By Ben Parrot - Landscape Gardener & Amateur Geologist


Cocoa shells mulch is a unique material when it comes to the world of decorative aggregates. A roasted by-product of chocolate making, it has emerged as a versatile, eco-friendly alternative for sustainable gardening. As a mulch, it truly stands out as an exceptional choice for weed control, as weeds either do not sprout at all or develop shallow root systems that can be effortlessly removed.

In this article, we explore the benefits and applications of using cocoa shells for mulching, demonstrating where it may be able to provide a valuable addition to your gardening toolkit.

Multicoloured cocoa bean shells. Jpg

Key Takeaways

  1. 1
    Acidic: Garden cocoa shells have a pH of 5.8, making them a suitable mulch for many acid loving plants, like rhododendrons.
  2. 2
    Nutrient-rich: Organic cocoa mulch, which contains nitrogen, phosphate, and potash is a great soil improver.
  3. 3
    Weeds Suppressant: An amazing, natural form of weed control.
  4. 4
    Pets: Cocoa shells contain theobromine, which is toxic to dogs. It will also deter cats, snails and slugs.
  5. 5
    Considerations: The innovation to mulch cocoa shell is an environmentally friendly option that promotes sustainability.
Confider in a planter with cocoa mulch. Jpg

Exploring Cocoa Shells

For avid gardeners, cocoa shell mulch is not only a practical choice but turns out to be a sensory delight. Notably, the roasting process of making chocolate products results in the presence of a delightful aroma and sterilizes the shells, guaranteeing them weed-free. However, it should be avoided by dog owners, as we cover later.

Size and Shape

Cocoa shells are generally small in size, with their uniformity in size making them a pleasing ground cover. The small size also enables better soil penetration, helping with water and nutrient absorption. The hulls are a flat, oval shape.

Cocoa bean shells mulch. Jpg


Cocoa shells come in shades of rich chocolate brown and coppery colours, making them ideal for flower beds and borders by adding a unique and consistent aesthetic to your garden. The color not only naturally complements plants, but it also tends to darken with time, as opposed to bleach-out.

Mulch cocoa shell with spring bulbs. Jpg

Key Features

Cocoa shell mulch comes packed with features that benefit both the environment and presentation of your garden. It has a pH level of 5.8, which can be very useful in maintaining certain types of plants ideal balance. It can also enrich the soil with essential nutrients like nitrogen, phosphate, and potash naturally.

A farmer husking cacao pods. Jpg

Aesthetic Appeal

This mulch adds an appealing aesthetic to your garden with it's wafting, sweet fragrance and attractive appearance. The smell usually lasts around 3-4 weeks. 

Practical Tip: Combine with other mulch, like garden bark or organic garden mulch, for a more textured appearance.

Acidic pH Balance

Cocoa mulch typically has a pH of around 5.8, which falls within the slightly acidic range. This pH level is suitable for many plants, and can help to maintain an optimal pH balance in the soil for healthy growth. It can also help to reduce alkalinity in soil which is excessively alkaline.

Practical Tip: Using litmus paper, or a pH indicator tool, measure the pH of the soil prior to use in order to create the right conditions for your plants.

Litmus paper strips next to soil and a shovel. Jpg

Nutrient-Rich Soil Improver

It contains nitrogen, phosphate, and potash, elements at a ratio of (3:1:3) which are essential for plant growth. When incorporated into the soil, cocoa mulch can improve soil fertility as it is slowly absorbed by the soil.

Practical Tip: To expedite decomposition, moisten cocoa beans mulch, periodically.

Flowering bulba in a pot. Jpg

Benefits of Cocoa Shells for the Garden

The benefits of using cocoa shells for gardens are manifold for gardeners, deterring pests, improving soils and acting as an amazing natural weed suppressant.

Deters Cats, Slugs and Snails

The texture of cocoa hulls is uncomfortable for cats to poop and walk on, making it an effective way to discourage feline intruders. Additionally, the rough surface of the mulch creates a barrier that deters slugs and snails, preventing them from reaching your plants as readily.

Cats are deterred by cacao shells. Jpg

Weed Control

Cocoa shells are very effective in weed control. Once wet, they gel together to form a loosely knitted porous mat below the surface. This creates a unique barrier that prevents weeds and deprives plants of the necessary sunlight for germination.

Practical Tip: Use in combination with a landscaping fabric for even better results.

Palms with garden mulch

Moisture Retention

A layer of cocoa shell mulch slows down water evaporation, and reduces water evaporation, helping to retain moisture so your plants stay hydrated for longer.

Practical Tip: Use around plants that require high levels of moisture.

Decorative palms in a garden. Jpg

Drainage Improvement and Erosion Prevention

One of the remarkable benefits of cocoa shells is that they improve drainage while preventing soil erosion. They create a loosely knitted mat on soil surface that lets water pass through while keeping the soil in place.

Practical Tip: Apply a thicker layer of cocoa shells on slopes for better erosion control.

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With its main application as a mulch for improving soil, suppressing weeds and helping to maintain soil temperature and moisture, we briefly, its uses in the next section.


Cocoa shell mulch is easy to spread and generally will not need topping up for many years. The mulch creates a protective crust, ensuring it remains in place even in windy conditions, offering a hassle-free ground cover that also effectively deters pests.

It also has enough nitrogen within to compost down, whereas uncomposted garden bark robs the soil of nitrogen, which can be harmful, especially to young plants. However, it should be used carefully to prevent excessive nitrogen release.

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Beds and Borders

Cocoa shells can be a great aesthetic and functional addition to flower beds and borders. The color and texture contrast well with plants, creating an appealing look while also providing all the benefits of an organic mulch.

Practical Tip: Use cocoa shells in combination with acid-loving perennials for a long-lasting, low-maintenance environment that is ideal for them.

1poppies growing in a field. Jpg

Need to work out how many cocoa shells your project needs? Try our free bark and wood chip calculator.


Cocoa shell mulch tends to decompose more slowly than other organic mulches like straw or bark. It maintains its color and texture for an extended period, making it a cost-effective option. The 'matting' can tend to crack in very hot weather, but recovers with rain or a blast from the hose.

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While cocoa shells offer a host of benefits, it's crucial to address some storage and safety concerns, particularly their theobromine content, which is toxic to dogs.

Potential Toxicity to Dogs

Cocoa mulch can be toxic to dogs, and potentially other pets if ingested. It contains two compounds that are known toxins to dogs: caffeine and theobromine. If you have pets that have access to mulched areas, you may want to consider an alternative mulching material or restrict the animals from these areas.

Practical Tip: If you have dogs, avoid using cocoa shell mulch, or use very carefully.

1a dog in a garden. Jpg


If you dampen the mulch upon application, they will form a crust and incorporate with the surface quickly. But it's crucial not to get the mulch overly wet. When cocoa shells are too wet and not allowed to dry out between watering, pests are attracted to the moist soil and mulch.

In humid climates, if the soil beneath cocoa shell mulch is already moist, avoid additional watering to prevent over-hydration. To address any harmless mould growth on the mulch's surface, use a solution comprising 25 percent water and 75 percent white vinegar, which can be sprayed onto the affected areas.

Practical Tip: Wear dark/old clothes to apply as the mulch can stain your clothing – just as a chocolate would.

1european robin in a garden. Jpg


However, if you are intending to store cocoa shell mulch for periods of time, sealing them in some kind of tub or container will minimise the chance of squirrels or mice chewing the bags, allowing the contents to spill out. Rodents like the smell of chocolate! It's also worth noting that cocoa shells can mold if they remain damp for an extended period, which could potentially cause respiratory issues for some individuals, so keep them dry.

Buying Cocoa Shells for Gardens

When it comes to purchasing cocoa shells for gardens, there are several convenient options. Many garden centres and nurseries that offer bags of cocoa mulch. Additionally, some online retailers and gardening websites offer it, although it's not as common as most of the mulches out there today.


Cocoa shells serve as a multi-faceted solution for a variety of landscape design needs. Not only do they also a great alternative visually, but their unique organic composition also facilitates moisture retention and acts as a very powerful weed control. However, it's crucial to consider potential pet toxicity before integrating them into your outdoor spaces.

1fresh cacoa pod sliced in half. Jpg


What are cocoa shells used for?

Cocoa shells are used primarily as a mulch in garden and landscape applications. They offer aesthetic appeal, weed control, and moisture retention, among other benefits.

Where can I buy cocoa shell mulch UK?

There are a few suppliers available online, although it's not as common as most of the mulches out there today.

What is shell cocoa?

Shell cocoa bean mulch refers to the outer husk that is removed during the cocoa bean processing stage, and it is usually converted into cocoa shell mulch for gardening purposes. The shell of a cocoa is commonly referred to by product name as the cocoa husk or cocoa pod husk.

Are cocoa shells good for the garden?

Cocoa shell mulch, often referred to as cocoa bean mulch, cocoa bean hull mulch, or simply cocoa mulch, is beneficial for the garden in several ways. They are aesthetically pleasing, help in moisture retention, and act as a natural weed barrier. However, they can be toxic to dogs, so caution is advised if pets have access to the garden.

Are cocoa bean shells a good mulch?

Absolutely. Cocoa bean shells provide an effective, attractive, and environmentally friendly mulching option. They help retain moisture and prevent weeds, making them an excellent mulch choice for garden beds and borders.

How long does cocoa mulch last?

Cocoa mulch is relatively long-lasting compared to other organic mulching options. It can maintain its aesthetic appeal and functionality for up to two years, depending on environmental conditions.

What are the disadvantages of cocoa bean mulch?

The primary disadvantage of cocoa bean mulch is its toxicity to dogs. Also, it can mold if left damp for an extended period, posing potential respiratory risks.

There are many wonderful types of wood chippings products available for your mulching needs. Check them out!

About the author 

Ben Parrot is a landscape gardener and amateur geologist. He is the founder of Outdoor Aggregates, with the mission to create the first encyclopaedia for decorative aggregates. From natural stone through to decorative bark, these aggregates are critical to garden and landscape design, universally.

The problem: There isn't any place where all the different types of decorative landscaping materials and construction aggregates can be found, nor are the specifications of each type readily available. So, enriched by his extensive experience, and inspired by the timeless elegance and raw beauty of stone and rock, etched by nature's artistry over millennia, Outdoor Aggregates was born.