Last Modified: April 6, 2024

Gravel Mulch

 the essentials of using stone as mulch

Slate chippings around the base of a tree

By Ben Parrot - Landscape Gardener & Amateur Geologist


Landscape gardeners and homeowners alike are always seeking innovative ways to enhance the beauty and functionality of their outdoor spaces, including creating walkways and driveways with different materials. One such method, growing in popularity, is the use of gravel as mulch, edging, or even aggregate for pathways and driveways. This article delves into the myriad aspects of using gravel mulch, exploring its benefits, considerations, and hardscape applications. Whether you are a seasoned gardener or new to landscaping, understanding how to use gravel mulch effectively can transform your outdoor area into a picturesque and practical space.

Finally, be sure to take advantage of our new 'Pebble Picker' utility, accessible from the sidebar or menu. This resource simplifies the process of selecting and perusing different decorative aggregates according to colour and type.

Hardy green plants with gravel mulch

Key Takeaways

  • Versatility: Gravel mulch suits various garden styles and offers multiple functional benefits, including aesthetics and practicality.
  • Durability: Unlike organic mulches, gravel mulch is long-lasting, requiring minimal maintenance or replenishment.
  • Weed Prevention: Effectively suppressing weed growth, gravel mulch also helps in preventing soil erosion in your garden.
  • Practical Tips: Get practical tips for effective and safe stone mulching.
Grey granite chippings around ornamental grasses in a front garden

What is Gravel Mulch?

Mulch is a layer of material applied over the soil, primarily around plants or landscaping features such as borders, paths or driveways. Gravel mulch is the application of small decorative chippings or pebbles as mulch. However, unlike other inorganic mulches, gravel is a naturally occurring material which means it blends seamlessly with the environment, without any toxic by-products entering the soil. It's available in a variety of sizes and colours, offering both aesthetic and functional benefits to your garden. With its unique characteristics, gravel mulch stands out as an alternative to traditional organic materials like wood chippings or shredded leaves.

Benefits of Using Stones as Mulch

As with any mulch, using stone for mulch on your beds and borders comes with a raft of benefits as well as some drawbacks which are worthy of your consideration. First up, we begin with the benefits:

  1. 1
    Adds Visual Charm: Available in various colours and sizes, gravel mulch can add depth, texture, and visual interest to your garden without overpowering other landscaping elements.
  2. 2
    Weed Suppression: One of the significant advantages of gravel mulch is its effectiveness in suppressing weed growth. Its density leaves little room for weeds to germinate, saving time and effort in garden maintenance.
  3. 3
    Moisture Retention: Gravel's porous nature enables it to hold moisture effectively against erosion, reducing the need for frequent watering. It helps protect plant roots from drought, particularly valuable during hot summer months when evaporation rates are high.
  4. 4
    Insulation: Gravel provides insulation to the soil, which helps regulate temperature and maintain consistency. This insulation is particularly important for the health of the roots, as it protects them from extreme cold during the winter and excessive heat during the summer. However, it is important to verify whether a particular plant species is suitable for hot and dry conditions before using gravel as mulch around it, as excessive heat buildup may cause issues if the plant is not adapted to such conditions.
  5. 5
    Pet Deterrent: Many gardeners use stone mulch to keep cats away, with the size and shape of gravel unpleasant for felines to use as a toilet.
  6. 6
    Enhanced Drainage: Gravel's excellent drainage properties prevent your site from waterlogging, promoting healthy root growth and reducing the risk of root rot or fungal diseases.

Next, we look at the different aspects of decorative gravel with regard to how to apply them in a creative way to improve the aesthetic of your garden or design your next feature.

Cotswold chiups and scottsih pebbles garden. Jpg

The Facets of Decorative Stone Mulch

Gravel is a versatile material for landscaping, available in various colours, sizes and textures, perfect for renovating your outdoor space. From blue slate mulch to marble gravels, there is something for everyone's taste. 

A gravel's texture affects walking comfort and adds visual interest to your garden. Choose wisely to create a beautiful oasis that reflects your individuality. Gravel mulch is both decorative and functional. It separates garden areas, prevents soil erosion, and provides drainage for plant health. Choose finer gravel for low-traffic areas and larger stones for pathways.

Decorative aggregates come in a wide range of colours, making it easy to choose the right one for your project. Neutral tones like Old English chippings or Rhinegold gravel offer flexibility, while bold colours like white marble chips or black basalt gravel can create dramatic contrasts. Consider blends with built-in contrast like multi spar gravel or Dalston gravel. They can provide a feature or an interesting contrast that ties in with surrounding plants.

So Many Colours to Choose From...

The variety of decorative aggregates available in the UK is second to none in the world. Still, knowledge about them can be limited for just about everyone, from professional landscape designers to DIY gardeners. To address this issue, our website offers the only comprehensive list in our encyclopaedia of decorative aggregates. This provides readers with access to the entire range of materials available for hardscaping in one convenient location.

If you have a specific type or colour in mind, you can use our colour picker tool to browse through all the available options and mix and match to your heart's content. Consider the gravel colour's appearance in different seasons and choose a shade that complements your garden and property's exterior. Go ahead, give it a try, and have some fun! (Feature coming really soon!)

Need to work out how much gravel your project needs? Try our free gravel calculator.

White and pink flowers in a garden. Jpg

Practical Tips for Using Gravel Mulch

When incorporating gravel mulch into your garden, consider the following tips:

  1. 1
    Depth: The optimal depth for gravel mulch depends on the gravel size. Smaller gravel (under 40 mm or 1-1/2 inches), ideal for pathway edging or as aggregate in a driveway, should be about 2.5-4 cm (1-1.5 inches) deep. Larger gravel can be laid more sparingly.
  2. 2
    Application Timing: Apply gravel mulch at the start of the growing season to maximise its insulating and protective benefits.
  3. 3
    Maintenance: Although low maintenance, periodically remove debris like leaves or dress the surface with new layers of gravel to maintain its appearance and functionality. This act is akin to updating the top layer of aggregates, much like you would with bark or compost in flower beds.

When using gravel as a mulch, it is important to ensure that the right depth is applied to achieve both effectiveness and aesthetic appeal. For gravel that is less than 40mm (1-1/2 inches) in size, a thickness of 2.5 to 4 cm (1 to 1.5 inches) is enough to provide adequate coverage without causing soil compaction. For larger gravel sizes, a variety of products can be used, including larger aggregates like 40mm slate chippings. A sparser layer is sufficient for larger gravel sizes, as the primary goal is to cover the soil and suppress weed growth. It is important not to place the mulch too close to tree trunks; instead, it should be placed outside the tree's drip line.

We have a step-by-step guide about How to Make Edging For a Garden which may be of great help to you.

Applying gravel mulch at the beginning of the growing season is recommended. This stabilises soil temperature and moisture levels, offers protection against fluctuating conditions of spring, and helps prevent weed germination. However, timing is less important with gravel mulch than organic mulches.

Maintenance, although minimal with gravel mulch, is still necessary. Regularly inspect the mulched areas for debris like fallen leaves or twigs. Removing such debris helps maintain the aesthetic appeal of your garden and prevents any potential breeding ground for pests or mould. This simple maintenance routine ensures that your gravel mulch continues to enhance the beauty and health of your garden throughout the seasons.

Gravel blend mulch around spring bulbs

Considerations and Drawbacks

While gravel mulch offers numerous benefits, it's important to consider its drawbacks and how they might impact your garden. While gravel mulch has numerous benefits, there are also some considerations to bear in mind:

  1. 1
    Cost: Gravel can be pricier than mulch, but it lasts longer and may be a better investment for larger areas such as driveways.
  2. 2
    Soil Impact: Gravel does not decompose or add nutrients to the soil, unlike organic mulch. Also, over time, gravel can compact soil, reducing its ability to absorb water and air, which are essential for plant growth.
  3. 3
    Removal: Gravel is more difficult to remove and replace compared to organic mulch.


One of the primary considerations is the cost. Gravel, especially decorative types, is generally more expensive than traditional organic products like compost mulch or decorative bark chippings. Although its longevity might offset this initial investment, the upfront cost is still a factor to consider, especially for larger landscaping projects.

Impact on the Soil

Gravel mulch does not contribute to soil health in the same way organic mulches do. It does not decompose, meaning it won't add nutrients to the soil or improve its structure. This lack of contribution to soil enrichment can be a critical factor for gardens that rely on mulch to enhance soil fertility.

Gravel is good for drainage, but too much can cause problems. Use around 5cm (2 inches) of 8-20mm gravel to allow proper water movement. Over time, gravel's weight can compact soil and reduce its health. Also, it may not be ideal for gardens with burrowing animals.


Another drawback is the difficulty in removal. Unlike organic mulches, which can be easily replaced or removed, gravel requires considerable effort and labour to clear away. This aspect is particularly relevant if you anticipate changing your garden's layout or design frequently.

Garden with small white flowers. Jpg


Gravel mulch offers a unique, aesthetically pleasing, and practical solution for garden landscaping. By understanding its benefits, types, and considerations, you can make an informed decision on whether gravel mulch is suitable for your garden. Remember, while gravel mulch has its advantages, it's essential to weigh these against your specific gardening needs and preferences to achieve the best results. Assessing your garden's specific needs and your long-term landscaping goals will help determine if gravel mulch is the right choice for your outdoor space.

Purple leaved shrub growing with pea shingle


How to lay mulch stones?

To lay gravel mulch stones, first remove weeds and debris from the area. Lay a heavy duty weed membrane to prevent weed growth. Spread the gravel evenly over the fabric to the recommended depth of 2.5 to 4 cm (1 to 1.5 inches) for small gravel and more sparingly for larger gravel.

How long does gravel mulch last?

Gravel mulch is long-lasting and doesn't decompose like organic mulches. It can remain effective for many years but may need occasional replenishment due to displacement or sinking into the soil.

How does gravel control weeds?

Gravel mulch controls weeds by creating a barrier that inhibits sunlight, reducing weed seed germination. The weight of the gravel also makes it difficult for weeds to push through.

How to prevent erosion with gravel mulch?

Gravel mulch prevents erosion by protecting the soil from wind and water runoff. Its weight and stability help to keep the soil in place, especially on slopes or in heavy rain areas.

How do you calculate the cost of gravel?

To calculate the cost of gravel mulch, determine the total area to be covered and the desired depth. Then, check local suppliers for the price per unit volume and calculate based on the required volume of gravel. OR, you can use our calculator and then compare suppliers right here in. the one place (feature coming very soon!).

We have every type of gravel available to choose from in the UK. 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.