How to Lay Cobblestone Edging

Using edging to define the edges of gardens, walks, driveways, and patios looks more formal. Compared to other edging options like brick, cobblestone edging provides a more natural look. Edging with cobblestones can be used to reduce the harshness of asphalt driveways, or to separate flower beds from lawns. Lawn edging prevents grass and weeds from spreading and protects landscape plants from lawn mowers and weed trimmers. In this article we will show you how to install cobblestone edging.

 

Measuring the cobblestones

A trench for edging should be measured by the cobblestones' width, length, and height. If the cobblestones are somewhat different sizes, use the largest one.

 

Spray an edge outline.

Spray the edging outline with landscape paint or a spare garden hose. To achieve a good fit, the outline should be 1/2 inch wider than the widest cobblestone. If the edge is straight, a piece of lumber can be used.

 

Making a Trench

Dig a trench as deep as you want the cobblestones plus 2 to 3 inches for a robust base material in the defined area. Trench to cobblestone height plus 2 to 3 inches for even edging on grass, cobblestones, and driveways. While some cobblestones may be left exposed, as in flowerbed edging, at least 1/3 should be buried to prevent shifting.

 

Fill the Trench with Gravel.

Fill the trench with 3-4 inches of crushed rock or gravel and press it down with a hand tamper. Add extra base material and pack it down if necessary to reach the desired base depth. Check the trench's level and add or remove base material as needed.

 

Mortar and Mix

Mix four parts masonry sand to one part cement mix with water to get a thick, soupy paste that doesn't easily slide off a trowel. Mortar is not required for informal edging like flowerbeds and sidewalks, but may be desired for roads.

 

Add Mortar to the Trench

Apply a 1-inch layer of mortar to the trench, starting at one end and extending to roughly five cobblestones.

Start laying the cobblestones.

Set the first cobblestone in the mortar, snugly against the trench and the pathway, garden bed, or driveway. Set it into the mortar with a rubber mallet, level it with a spirit level, then add or remove mortar to make the stone level. The same method works for cobblestones without mortar; tap the stones down and push them against the trench's end and each other with a mallet.

 

Keep laying the stones

Continue with the next four cobblestones, gauging level with your sight. Tap the cobblestones with the rubber mallet to close the gaps between them. Lay a level across the first five cobblestones and add or remove mortar to obtain level edging.

 

Install the remaining cobblestones across the trench, checking for level every five cobblestones.

 

Fill any remaining end gaps.

If the trench is too small for a whole cobblestone, measure the remaining gap. Score a cobblestone with a cold chisel and hammer all over to break it into tiny pieces, then set it in place as before.

 

Fill up the edging spaces with soil and compact it hard.

 

Add Sand to the Edging

Pour polymeric sand over the cobblestone edging and use a broom to push it into any leftover spaces between stones. Polymeric sand contains polymers that harden when exposed to water, keeping the stones stable.

 

Tip

Tie a stringer to wooden stakes set at the correct height for the stones. Ideally, the top of each cobblestone should hit the string line, but it may be easier to just follow the surrounding pathway, road, or garden bed.