Your guide to choosing rocks and plants for a rock garden

You can create a rock garden of any size by working with an existing stone outcrop or by arranging rocks and filling the crevices between them with compost and gravel. Use these tried-and-true guidelines for creating your garden of stone.

Rock gardens are modelled on high-mountain terrain, where colonies of alpine wildflowers and shrubs thrive on the cool, sunny, arid stone slopes.

A steep, hard-to-mow slope is an ideal setting for a rock garden and it can easily be transformed from an eyesore into a showpiece.

• Structure the base of the slope with a low stone wall, then work your way up the slope by adding more stones and plants.

To help your garden of stone fit into the landscape, choose a type of rock found in your region and use it throughout the garden.

Place stones in odd-numbered groupings, which are usually more eye-catching than even numbers. On a steep slope, use the largest stones for the base.

• As you set stones in place, plant them by burying them one-third of their depth in the soil with the broadest side down. This will keep them from toppling.
• Slant stones so that they point backwards, which channels water to plant roots and prevents erosion.
• Be sure to include a few flat stones to stand on when you're working in your garden.

Plants used in rock gardens are traditionally tough alpine wildflowers, along with ground covers and dwarf shrubs, but you can use any low-growing plants to complement mountain natives.

• For visual interest, choose a variety of plants that have different growth habits.
• Mix creeping perennials with upright bulbs and add in other tiny bloomers.

Dwarf perennials are mainstays of the rock garden.

• Choose among dwarf ferns, sempervivums, saxifrages, campanulas, tiny bulbs and creeping phlox.

• Put spreading plants in their own pocket to keep them contained.

Rock crevices form natural barriers against spreading roots.

Adapted to harsh conditions, rock plants are accustomed to quick-draining soil. Heavy soil will suffocate the roots, while rich soil promotes lush growth that may overtake the stones.

• Fill crevices with a mix of coarse sand, compost and fine gravel.