| Posted: Saturday, May 12, 2012 06:00 am
Concrete curbs that appear to follow the swales and contours of the landscape can add a touch of natural beauty to a garden at the same time as they make yard work easier.
At their most basic, concrete curbs are used as permanent dividers between the grass and the flowers. Curbs can be more than concrete edging because the structures themselves may appear to look like wood, they may be coloured or they may look like bricks or cobblestones.
"They tie everything in and at the same time add a formal finish. Concrete curbs minimize the amount of work in the yard and the lawnmower can run right over them. And of course, they are permanent," said Kwik Kerb franchise owner Kari Halls.
Halls, who is from Morinville, took over the family-owned Kwik Kerb business some years ago and does her own concrete work.
First she cuts a seven-inch wide, one-inch deep strip through the turf and uses a concrete extruder machine to make a moulded curb that sits on top of the ground. If there is existing plastic edging, she leaves it in and follows the line.
"The curb flows with the ground and moves like a snake," Halls said.
Expansion joints are placed every few feet to accommodate winter freezing and thawing cycles. The only problems arise when the curbing encloses tight circles that do not allow room for expansion.
"If you have too tight a circle, when it freezes, it can push out and crack," Halls explained.
These curbs also work best in older yards where the ground is settled.
Curbs do not have to be concrete-grey. They may be brown or red or charcoal coloured and they may have patterns stamped into them. Coloured, patterned curbs are stronger than plain curbs.
"I've seen some yards where they combine the coloured curbs with orange or blue shale and the colours pop like crazy and look really good. The coloured concrete is harder because the colour goes on top of the plain mix. It acts like a sealer," she said.
One pattern has a wooden finish that resembles roof shakes. Other styles look like brick or paving stones.
The curbing is not a retaining wall and allows normal drainage to occur.
"Water shouldn't pool behind it. The only thing to remember is, it is concrete, and it has to cure for a few days. It's just like a city curb beside your sidewalk," Halls said, adding that some gardeners still cut a narrow edge beside the curb.
"Grass will keep growing over it, so some people like to use an edge cutter every three years," she said.
A different permanent edging style is achieved by Greentree Landscaping of Edmonton.
This company digs a trench where the edging will be placed and fills the hole with concrete. Then the concrete is faced with cobblestones, slate or an exposed aggregate mix that lends the surface a more natural appearance.
The edging may be placed as a finishing touch on the side of patterned driveways or patios or it can be used to enclose flowerbeds.
In yards where there is a sump drain between two adjacent properties, Greentree has used concrete curbing to create a ditch that looks like a dry creek bed. The drain serves as an important function in both yards, but by filling the concrete ditch with large fieldstones, and sloping it gently down away from the properties, it looks as if it is part of the landscape.
This style of edging is usually left flush with the ground.
"By making it flush with the ground we don't have worries about winter heaving. If the ground goes up, it goes up," said Gordon Neustaeter, a landscape designer with Greentree Landscaping.
The natural look has a feng shui style to it that seems in tune with nature. The curbing seems to hug the land, and looks as if it has always been there.
"The goal," Neustaeter said, "is to make it look as if it wasn't a fleeting afterthought but instead to make it an integral part of the yard."