Last Modified: February 7, 2024

Black Slate Chippings

Versatile Elegance for Landscapes

Black slate chippings

By Ben Parrot - Landscape Gardener & Amateur Geologist


Slate landscaping material and construction aggregate

Geological name(s):

Phyllite and schist

Other Name(s):

Black slate, charcoal slate, black slate chips, black garden slate, black garden slate chippings


Black slate chippings have a sleek appearance synonymous with contemporary elegance, yet they are more than just aesthetically pleasing - they also serve many practical purposes in outdoor design. This encyclopedia page offers a comprehensive understanding of the key specifications, advantages, and multifaceted uses of black slate chippings as a landscaping material and construction aggregate.

This listing also serves as a portal to an array of resources, including a list of 'similar to 'alternatives, articles for inspiration covering fundamental design principles as well as a variety of do-it-yourself instructables for building your own decorative aggregate features.

Black Slate Chippings Specifications





fall safety





fish friendly

eco friendly



diy friendly






Dark grey to black


Flat, angular

Close up of slate black. Jpg

Size Range

10-40mm (0.4-1.6 inches)
Black slate chippings 20mm, black slate 40mm, black slate chippings 40mm

Fall Safety

Unsuitable for play surfaces





Fish Friendly


Black slate chippings close up









Black slate garden path


Decorative aggregates like black slate chippings offer numerous benefits in garden and landscaping designs. They are a versatile, low-maintenance option for enhancing the aesthetic appeal of outdoor spaces. Black slate chips aid soil moisture retention, prevent weed growth, and provide a natural, elegant finish to gardens and paths.

Specifically, with their dark, sophisticated hue, black slate chippings bring a contemporary edge to garden projects. Their flat, angular shape ensures stable footing and creates an attractive contrast against green foliage and bright flowers. The colour of these chippings remains vivid and striking, especially when wet, making them ideal for water features and fish ponds.

  • Inhibits weeds
  • Improves drainage
  • Hard-wearing
  • Eco-friendly, sustainable
  • Low-maintenance
  • Moisture retention
  • Versatile all-rounder
  • pH neutral
  • Quick space transformation
  • Safe for aquatic life
  • Root protection
  • Easy to lay


Black slate chippings are particularly suited for contemporary garden projects, such as rock gardens, ornamental water features, and fish ponds. Their dark, elegant appearance can also enhance the visual appeal of your front garden, be it in raised beds, borders, or as a mulch alternative. Keep in mind the need to wash the chippings before use in fish ponds.

In the following section, we list many common black slate chippings uses, although it is not exhaustive. Wherever there is a hyperlink beside an item, an article from Outdoor Aggregates about the topic is available.

Slate chips garden

Inspiration and Informational Articles

DIY-Friendly How-To Guides

Need to work out how many stone chippings your  project needs? Try our free gravel calculator.

Other Applications

Some other excellent applications for black garden slate chippings include:

  • Base for terrace, patios or outdoor seating areas
  • Slate aquarium caves
Black slate chips under leaves in a garden. Jpg

Unsuitable For

The following list represents the kinds of applications that charcoal slate chippings are not suitable for:

  1. 1
    Decorative borders featuring trees or shrubs that may be vulnerable to extreme heat or require a large amount of water.
  2. 2
    Black slate chippings are unsuitable for french drains because there are cheaper options. 
  3. 3
    Play surfaces
  4. 4
    Areas requiring high foot traction.

Similar Alternatives to Black Slate Chippings

The following is a list of decorative aggregates which are alternatives to black slate chips. They may offer you a more suitable variation on the primary colour, a more economical option, or a close substitute for cases where the base material may be unsuitable for the project you are creating, e.g. limestone is not fish-friendly, where slate is.








charcoal grey


10-20mm (0.4-0.8")



grey, blue

10-40mm (0.4-1.6")

flaky, flat



10-50mm (0.4-2")



dark grey


5-20mm (0.2-0.8")



black, grey


10-20mm (0.4-0.8")



Under £80







Cleaning dead leaves from slate chips garden

Black slate chippings are generally low maintenance, especially when a heavy duty membrane is installed underneath to suppress weeds, with most work limited to raking and the occasional removal of debris. Occasional power washing is advisable to maintain the original colour and prevent algae or moss buildup. Natural quarry materials also may have dust, which should be hosed off with water at the time of installation. When using for aquariums and ponds, wash prior to use for ensuring safety of aquatic life.

For areas with heavy footfall, such as paths or footpaths, replenishment of chippings may be required over time to maintain depth and coverage. For more on how to clean stone chippings, read our article: how to clean garden stones.

Purchasing Tips

Natural slate landscape england

When purchasing black slate chippings, consider the size and quantity necessary for your project. When purchasing green slate chippings, consider the size and quantity necessary to achieve the right coverage for your project. Slate chippings come available in a range of sizes from mini mulch, ranging from 2-14mm, 20mm, 40mm, 60mm and larger diameter. Also, consider the size you'll need; for instance, black slate chippings 40mm are typically used for driveways and borders, while black slate chippings 20mm or less in diameter are better suited to footpaths. Where available, it is cost-effective to request a sample to assess the stone's colour and quality against your design requirements.

Using our gravel calculator to get an unbiased estimate for your project needs is one of the best and easiest ways to get the right amount without the risk of shortfalls or over-spending - all you need is a few measurements of the space. Ordering in bulk bags is often more cost-effective than smaller quantities. When purchasing any landscaping materials, requesting an official notification of information about the delivery times for bulk bag deliveries is also advisable.


Can you use slate chippings for drainage?

Slate chippings are effective for drainage purposes due to their permeability and ability to promote water flow. There are many more inexpensive options, making them an expensive but effective choice for drainage systems.

How much will 1 ton of slate cover?

One ton of slate will generally cover an area of around 7 to 9 square meters when applied at a depth of 5 centimeters, providing sufficient coverage for most common applications.

How thick do you lay slate chippings?

Slate chippings are typically laid at a thickness between 2-4 inches, depending on the type of feature, to ensure proper coverage and stability. The minimum thickness provides both aesthetic appeal and practical functionality.

Do I need membrane under slate chippings?

Yes, a weed control membrane is recommended to prevent weed growth and ensure stability.

Do slate chippings stop weeds?

Although they may not completely eliminate weed growth, using a membrane significantly reduces it.

Is slate better than gravel?

Slate is as durable and colour-fast as gravel, therefore there is no superior choice for longevity or aesthetics.

How deep should slate chips be?

A depth of 40-50mm (1.6-2 inches) is ideal for adequate coverage.

What are the colours of slate chips?

Slate chips primarily come in shades of blue, purple, green, grey and black.

Does black slate fade?

Black slate maintains its colour well, especially when regularly washed to remove dust and dirt.

There are many other varieties of stone chippings available for your project. Check out 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.