Decorative cement edging adds definition and structure to a landscape. Unlike metal, plastic or metal edge restraints that are often painted green to blend in, cement edging brings a contrast of colours and textures. Using cement edging to create tree rings can establish one tree as a focal point or tie multiple trees into paved features of the landscape.
While installing cement edging involves more steps than strips of edging restraints, it's also longer lasting. Cement doesn't rust and holds up against harsh weather better than plastic. Wet cement installed with an extruder machine offers a continuous border that effectively blocks encroachment. Cement also offers a wide array of design options, whether you want a soft look with rounded corners or a surface that resembles bricks or cobblestones.
The standard design for a tree ring is basically round, but the versatility of cement allows you to customise the look to complement your landscape style. Consider tinting the cement with a colour agent or using coloured sealer over the finished ring. Give the surface the appearance of brickwork or natural stones by stamping the ring with a textured rubber mat.
Installing cement tree rings is a basic do-it-yourself project you can complete in an afternoon. An extruder machine makes it easy to install a continuous border once you dig out the foundation. The foundation should be about 8 inches deep and 6 inches wide. Use a 4-inch layer of gravel as the base to allow moisture to escape and prevent the cement from cracking. The gravel will also prevent roots from encroaching underground, taking water and nutrients away from the tree.
Plan the diameter of the edging to fit the estimated size the tree will be upon maturity. If the tree ring is too small, it can interfere with the roots. When scaled correctly, the tree ring will protect exposed roots from the lawnmower and you can fill in the ring with topsoil and mulch to reverse erosion.