Build a rock garden for a hardy outdoor design

Ever thought of the numerous aesthetic and practical advantages rock gardens can bring to your landscape? Building a rock garden will bring a lovely natural effect to your outdoor area, while also providing stability to sloping areas.

Garden designer Jake Adamsons, from Rock Steady Landscapes in Melbourne, is often called upon to create rock gardens for his clients. But he's also happy to provide some advice to people thinking of making their own. So, if you've been wondering how to make a rock garden, read on...

Will a rock garden suit my outdoor space?

"The best place for a rock garden is in a sloping garden," he says. "The rocks can replace a basic retaining wall of timber or brick in order to stabilise the bank. And obviously the visual effect of a rock garden is entirely different to that of a retaining wall. It's much more natural looking."

What type of rocks should I choose?

The type of rock or stone you choose for your rock garden will depend on your taste. Do you want a native and natural look, as if it was meant to be there? If so, then native or local rock will work best. If you want the rock garden to stand out as man made, then choose imported rocks such as granite, marble, bluestone or slate.

What's the best way to build a rock garden?

Jake recommends putting larger rocks at the base of the slope and making them progressively smaller as you move upward. This is for practical reasons - to help stabilise the bank - and also to create a natural tumbling, cascading effect. He suggests burying each rock at least a quarter to one-third into the soil.

Try to ensure that the soil you have between the rocks is well drained rather than full of clay. Well-drained soils are less likely to absorb water and destabilise the bank, and are better suited to a wide variety of plants.

Which plants are suited to rock gardens?

Speaking of plants, it's good to choose a mixture of groundcovers, smallish shrubs and perhaps one or two feature plants (these could be mid-sized trees such as Japanese maples, tree ferns or silver birches).

Rock gardens often have quite shallow soils, so groundcovers are particularly important. Jake recommends Golden Guinea Flower, a hardy groundcover with dense foliage and yellow flowers; Trailing Pratia, with its carpet-like effect and pretty flowers in white or blue; and Red Passion Flower, a vigorous and hardy vine with red flowers.

Can I include other elements for interest?

Other natural elements like timber work well in rock gardens. Think of the effect a boardwalk between the rocks or a series of small floating decks might provide. Water is another element perfect for rock gardens, either sitting still in a bowl or small pond, or trickling down through the rock garden as a stream or waterfall.

Get started on building a rock garden or find a landscaper to help you with your rock garden design: