How to Build a Rockery Garden Step by Step

A rockery is a great way to add structure, texture and year-round interest to any outdoor space. They’re also low-maintenance, so ideal for gardeners who want to create an attractive feature without lots of upkeep.

Whether you're dealing with a tricky slope or an uninspiring garden corner, a rockery can completely transform the space. They are perfect for showcasing alpine plants and other species that thrive in rocky, sunny environments. Plus, rockeries can improve drainage and make the most of awkward or uneven terrain by creating a microclimate to support growth.

From rugged stone centrepieces to vibrant plant displays, here’s everything you need to know about building a garden rockery – from initial planning to final planting.

Designing a rockery

Like any great landscaping project, building a rockery starts with careful planning. Choose a sunny spot on sloped or level ground with good drainage. Avoid shaded areas under trees, as most rockery plants, especially alpine varieties, need plenty of sunlight and minimal moisture.

Think about how your rockery will work alongside existing features like patios, garden walls or borders. Choose stones and gravel that complement your garden’s current colour palette and textures. If you’re lucky enough to have a natural rock outcrop or slope, even better – you can build your design around it.

Sketch a rough plan marking the shape and size, any access paths and planting zones. It doesn’t have to be technical but will help visualise the layout and create a cohesive design.

Tip: Want to achieve an organic design that will blend seamlessly into your garden? Avoid straight lines and neat patterns, and instead group rocks in odd numbers and vary their sizes.

What you’ll need to build your rockery

Having the right tools and materials ready before you start will save time and effort, so make sure you have these to hand:

Tools:

• Spade (for digging)
• Wheelbarrow (for moving materials)
• Rake (for levelling)
• Gloves (for handling rough stone)

Materials:

• MOT Type 1 aggregate or coarse gravel – to create a sturdy, permeable sub-base
• Weed membrane – to prevent weed growth while allowing water to pass through
• Rockery stone – a mix of feature stones and smaller rocks for depth and character
• Topsoil – free-draining soil for filling between rocks and in planting zones
• Potting mix – an Alpine-specific compost blend like Westland Alpine Potting Mix
• Decorative gravel – a long-lasting mulch option to complete the look while suppressing weeds and protecting plants against pests.

Whether you're starting from scratch or enhancing an existing feature, AWBS can supply the landscaping materials you need. Visit our branches in Oxford, Yarnton and Swindon to collect what you need and get expert advice, or order online. Our sister company Oxford Garden Centre also stocks a range of quality planting soils and rockery plants, so be sure to call in.

Choosing the right rocks and gravel

The stones you choose are the foundation of your garden rockery, so it’s important to get the balance right. The best rocks combine practical benefits (like drainage and durability) with visual appeal. Choosing locally sourced stone in a mix of sizes can also help your design blend more naturally with its surroundings.

AWBS stocks a wide range of rockery stones in sizes from 150mm to 700mm, ideal for achieving a varied, layered effect. Popular rock types include:

• Limestone: Traditional choice, creamy tones, ideal for alkaline soils
• Sandstone: Weathered look, various warm hues, easy to work with, affordable
• Slate: Flat, layered texture for a sleek and modern finish
• Granite: Extremely hardwearing and bold finish – great for visual impact

AWBS offers a wide selection of rockery rocks, including rustic Yorkstone and buff-toned Cotswold stone and cooler-toned grey Longstone limestone and textured slate. We also supply slightly larger rugged options like Cambrian granite cobbles and smooth, rounded Scottish beach boulders for a more contemporary look. Whichever you choose, match your stones with a top-dressing of decorative gravel for a cohesive finish. We stock over 30 types of decorative gravel, stone chippings, and pebbles, available in small and bulk bag quantities.

Best plants for a rockery garden

Rockeries are perfect for plants that thrive in sunny, well-drained conditions, especially hardy alpine plants adapted to mountainous, dry environments. However, you can also mix in low-growing perennials, ornamental grasses and even small shrubs for variety as you see fit!

Popular plant choices:

• Alpines: Saxifraga, Sempervivum (houseleeks), Aubrieta, Campanula
• Ground cover: Creeping Thyme, Sedum (stonecrop)
• Grasses: Festuca glauca (blue fescue), Carex varieties
• Small shrubs: Dwarf conifers, heathers
• Spring bulbs: Dwarf Narcissus (daffodils), crocus

For best results, choose a mix of foliage textures with staggered bloom times to ensure continuous colour. Tuck plants into crevices for shelter and moisture retention, while still ensuring they get a good amount of sunlight through the day.

For inspiration and expert plant advice, visit our sister business, Oxford Garden Centre, located next to AWBS Oxford. Their feature garden, complete with a rockery and water feature, is a fantastic example of what can be achieved! The centre also stocks a host of suitable garden rockery plants and potting mixes.

How to build a rockery from scratch

Got everything you need? Read on as we break down the steps of building a stunning, low-maintenance rockery packed full of texture and colour.

Step 1: Clear and prepare the site

Mark out the area for your rockery using sand to create a clear visual guide – or you can use pegs and string. Remove all grass, weeds (don’t use chemicals) and roots to expose bare soil, then dig down about 20cm – this is where you’ll lay the foundation. On level ground, dig slightly deeper at the front to form a gentle slope for drainage and better visibility.

Step 2: Create a solid base

Next, lay a sub-base of MOT Type 1 aggregate or coarse gravel about 15cm deep. Don’t compact it too tightly, as you want water to drain through easily. On top, add a layer of permeable weed membrane to stop weeds coming through and keep the soil above in place. Then, add a layer of weed-free topsoil, deep enough to bury a third of your rocks for stability. This should ideally be made from equal parts compost, sharp sand and grit.

Step 3: Position large feature rocks

Once the base is ready, you can start to the lay the rocks. Arrange the biggest rocks first as keystones that will shape the overall structure. Do so randomly and using a range of sizes and heights, digging small hollows in the soil to nestle each rock for stability. Bury around a third of each rock in the soil and angle them slightly backward to aid water runoff. Then fill in the gaps with smaller stones, remembering to leave strategically placed planting pockets for later.

Tip: a crowbar can be handy for adjusting heavy rocks, especially if you’re working alone.

Step 4: Add a soil mix ready for planting

Fill planting pockets and crevices with a free-draining soil mix, such as the Westland Alpine Potting Mix from Oxford Garden Centre or more of AWBS’s planting soil blend. Once filled, soak the entire rockery well and allow it to settle for a few days before planting.

Step 5: Get planting

Start by checking the soil pockets – the soil mix may need topping up once it has settled. Remove plants from pots, loosen the roots and plant at a similar depth to the pot. Fill gaps with compost, firm gently and water lightly.

Then top-dress your plants with a 2cm layer of decorative gravel mulch. This will help to keep weeds at bay, deter pests and protect the roots from temperature changes throughout the seasons. AWBS stocks flint, slate and quartz chippings and more in various colours and sizes. Better yet, 23kg small bags are now 5 for the price of 4!

Once established, plants in crevices will need minimal watering thanks to the natural shelter and moisture retention. Just deadhead and prune your plants as needed to keep things tidy.

Ready to build a rockery of your own?

With the right materials and plants, your rockery will be both beautiful and low-maintenance. All the products you need, from rockery stones and topsoil to decorative gravel, can be conveniently ordered online or purchased in-store at AWBS. Meanwhile, alpine rockery plants and a wider variety of composts can be found at our sister store, Oxford Garden Centre.

We can also provide impartial advice and arrange free delivery within 25 miles of our branches in Oxford, Yarnton and Swindon. Start your rockery project today with the help of a trusted and knowledgeable local stone supplier – AWBS.