Recipes for rock (Spring 2006)

Elaine Unguran of Canar Rock Products in Edmonton, Alta., says a little planning will go a long way to taking advantage of what stone can bring to a yard project. “Fifteen years ago there were five or six choices for the do-it-yourselfer. Today’s home-owner has a lot of choices to make, but that’s an improvement. Stone is being done much better today because of it,” she says.

Grant Wood of the University of Saskatchewan says rather than creating horticultural problems with trees and plants that won’t ever live up to their potential due to troublesome locations, stone can be used instead. “Sometimes, when you’re designing your yard, you need to consider those locations where plants won’t work all that well. Why invite problems with weeds and slow growth? That’s where stone is a natural fit. It can be used to control weeds and allow water to be better managed,” he says.

Smaller stones such as pea gravel that are less than 1/2 inch in diameter can be used like wood chips or leaf mulches, but without adding disease or being affected by wind. Landscaping fabric should be used to control weeds and to prevent the stone from mixing with dirt in areas where water is expected to drain into the soil beneath the stone. This applies to flower beds, borders for lawns, and under shrubs and trees.

For a clean look along foundations, pea gravel can be used to disguise the black plastic used to prevent weeds and excess moisture from accumulating next to concrete walls. Pea gravel that is sloped away from the house foundation or other concrete structures such as driveways, prevents wind and water erosion while maintaining a tidy boundary between plants and the building.

Other stone mulches include small river-rock, also known as rainbow rock, due to its variety of colors and coarse sands. Red shale has become very popular with landscapers looking to add color to rock gardens or as a permanent mulch around plants.

George Klassen of Saskatoon’s Inland Aggregates agrees, saying that using the appropriate stone for the job can be very important. “Driveways, for instance, are best created using crushed road-base. It’s coarse and allows drainage. Best of all it’s economical and won’t need much maintenance,” he says. Klassen says septic fields benefit from washed rock in 1/2 to 1 1/2-inch diameters. “It gives excellent drainage and won’t settle or erode easily,” he says.

The size of the rock often dictates its most appropriate use. Sand is a clear example. Fine sand provides weed control, safety, and creates sandbox areas around play structures. It can also be used with a mix of clay for informal walkways that are packed to form a semi-solid, water-repellent surface. “Coarse sand is better-suited to exercise areas for horses where you don’t want it pack hard,” Klassen explains. Walks and paths are traditionally the home of fieldstone and slate that are laid over machine-packed paths of sand.

Slate’s more formal look makes it an attractive option to fieldstone, but needs to be 1 1/4 inches thick or more to resist fracturing. Flagstone is tougher than slate, so thinner thicknesses can be used for walkways.

MacKay recommends having larger stones power-washed with soap or other cleaning solutions and then thoroughly rinsed. He says that the trend toward using more stone gives people a base to be creative. “It’s allowing homeowners to invest more in some unique grasses and other native plants. People are also learning to create arid garden spaces that are gentle to the environment. Even cacti gardens in northern climates look natural due to stone.” “Stone, like water, is naturally present in most landscapes. We’re finally learning to put it back into our surroundings,” he says.