20mm Blue Slate

Blue Slate is our most popular choice of Welsh Slate, known for its striking dark blue tones, which often carry a subtle plum-like undertone. This elegant slate is a favorite amonst our decorative stones range for garden borders and decorative features, adding texture and depth to any outdoor space.

Natural and Unique
Quarried in North Wales, this rustic slate boasts a naturally angular shape with flat surfaces. Some edges have been gently smoothed by water, enhancing its aesthetic while keeping a rugged, authentic feel. Each piece averages 20mm in size, making it perfect for foot-friendly garden pathways and decorative displays.

Fish-Safe and Lime-Free
Welsh Blue Slate is entirely lime-free, ensuring it is safe for use in ponds or aquatic environments. This makes it an excellent option for landscaping around water features or fish ponds.

Available Sizes
For larger applications or a more dramatic effect, this slate is also available in a 40mm size. Click here to learn more about the 40mm Blue Slate option.

Transform your garden with the timeless charm and versatility of Blue Slate!

20mm Blue Slate Features

• Great for garden borders or features
• Best-seller for years
• Locally-sourced
• Fish-friendly

20mm Blue Slate for Your Garden

Blue Slate offers numerous versatile and attractive uses for your garden. One of the most popular applications is creating a decorative border around your home. By leaving a 20cm gap between your landscaping elements—such as turf or paving—and filling this space with Blue Slate, you can achieve a clean and polished look that enhances the overall aesthetic of your outdoor area.

Low-Maintenance Garden Features
The 20mm Blue Slate is perfect for adding a striking garden feature that requires minimal upkeep. For example, if you have a small front garden that you don’t frequently visit but still want to maintain its visual appeal, Blue Slate is an excellent choice. It is easy to install and can be laid over a weed membrane, reducing the hassle of weeding and ensuring a neat, tidy finish.

Blue Slate is not only practical but also delivers timeless beauty, making it a reliable option for enhancing pathways, borders, or standalone garden features.

20mm Blue Slate for Commercial Use

Our 20mm Blue Slate has been supplied to a variety of businesses, including car parks, public parks, and caravan sites, where it serves as an attractive and durable solution for areas that are lightly walked on and frequently admired. Many outdoor spaces, such as cafes with al fresco dining areas featuring ponds or water features, have also incorporated our Blue Slate to enhance their ambiance.

One of the standout qualities of Blue Slate is its transformative effect when used in ponds or water features. The water amplifies its natural beauty, deepening the plum and blue tones, creating a rich, vibrant effect that catches the eye. Whether you're designing a garden pond or a simple water installation, Blue Slate brings texture and striking color to your project.

Additionally, our Welsh Blue Slate is lime-free, making it completely safe for wildlife, ensuring your pond or water feature remains eco-friendly and suitable for fish or other aquatic life. This makes Blue Slate a practical and aesthetic choice for both commercial and residential landscapes.

How to Buy 20mm, Blue Slate

20kg maxi bags 

850kg bulk bags (approx weight)

This stone can be collected for free at one of our depots in Wimborne, Bournemouth, Christchurch or Dorchester, or these garden stones can be delivered nationally to anywhere in the UK.

You can use our Stone Calculator to work out how much of this stone you need - simply enter the measurements of your garden, the depth at which you want to lay the stone and it will work out how much you need!

How to Create a Garden Pond 

The trend for garden ponds is growing, with options to suit every style. Whether you prefer a small, structured pond surrounded by paving or a more natural, wildlife-friendly water feature, adding a pond can transform your outdoor space. Follow our guide for tips and tricks to make it happen!

1. Plan Your Pond Location

Choose the ideal spot for your pond:

Avoid trees: This reduces debris like leaves falling into the water and keeps it clean.

Sun and shade balance: Ensure the location gets some sunlight but also offers shaded areas to keep the water cool and inviting for wildlife.

2. Decide on Size and Type

Determine the size and type of pond that fits your garden:

Ground-level pond: Use a pre-formed plastic pond liner available from garden centers. Outline the area with spray paint to match the liner's shape before digging.

Raised pond: Create a raised pond using retaining sleepers, lined with a heavy-duty plastic sheet. Alternatively, upcycle old materials, like an unused tire, for a unique and budget-friendly option.

3. Prepare the Area

For a ground-level pond:

Dig the area to match the depth and shape of your pond liner.

Once the liner is in place, fill any gaps with scalpings or soil for a secure fit.

For a raised pond, ensure the structure is sturdy and sealed before adding water.

4. Add Water

Begin filling your pond:

Use tap water or collected rainwater.

Consider adding a water pump (plug-in or solar-powered) for a small fountain or circulating water feature to enhance aesthetics and oxygenation.

5. Decorate and Finish

Enhance your pond with decorative elements:

Start with larger stones, such as Blue Slate Rockery, around the edges. Add smaller stones like 20mm Blue Slate for a layered look.

Incorporate water plants like lilies, reeds, or oxygenating plants from your local garden center to create a natural, thriving ecosystem.

Enjoying Your Garden Pond

By following these steps, you’ll have a beautiful, functional pond that enhances your garden’s appeal while encouraging local wildlife.

Pro Tip: Decorative stones, like slate, are naturally sourced and may arrive dusty. Hose them down after installation to reveal their true color.

Make your pond a standout garden feature while supporting the environment and enjoying the calming presence of water in your outdoor space!

Buy With Confidence

• Our 20mm Blue Slate can be purchased in 20kg maxi bags or bulk bags that weigh approx. 850kg
• Not sure how much you need? Use our quantity calculator and enter your garden width and length to find out how many maxi bags/bulk bags you need! 
• Please select the bag size you'd like to buy and add it to your basket 
• Our aggregates will either arrive on a HIAB lorry that can be used to lift the stone onto your garden, or it will arrive on a pallet for kerbside delivery; depending on your address
• You can choose a free collection from one of our Depots or fuss-free, home delivery.

A Service You Can Rely On

• Our reliable service offers prompt delivery to any area in the UK
• Stone Zone is a family-run business that has been well-established since 1998
• Our efficient customer advisors can help you with your purchase
• We pride ourselves on offering a range of affordable garden supplies 

Sample stones are available in-store and online, please ask a customer advisor. 

A Delivery Service Tailored to You

Our top-rated delivery service is flexible and reliable to suit you, however, it can vary depending on where you live. Click here for more information on our delivery service and if your postcode is classed as 'local' or 'national.'

Any questions? Use our live chat to speak to an advisor, alternatively, you can fill out an enquiry form or call us on 01202 874207.