Life on the Edge
A defined edge between turf areas and mulched beds makes the yard look better and adds curb appeal. The best way to create an edge for a mulched bed is the old-school, old-money way called trench edging. It is also the cheapest and best looking border between shrub beds and turf areas. You can dig a trench straight down three inches along the grass edge and then scape four inches wide across the bottom of the trench. The slope on the inside of the trench near the shrubs can slant up toward to the planted bed to catch loose, migrating mulch. By catching all the loose mulch, it doesn’t feather out into the surrounding turf. Dump the extra soil on the mulch side of the trench for even more of a defined look to the trench. The rain will flatten clods in just a few days. The nice, deep trench provides a good, solid delineation of the ground plane, which always looks great in the landscape.
This is inexpensive compared to purchasing and installing commercial edging material. The only cost is the shovel and the labor. It looks quite elegant! A substantial trench edge makes a strong statement—you maintain your property to the highest quality standards.
Some contractors use a v-shaped trench – a halfway measure that doesn’t look as nice. Once the initial cut straight down is made, the rest is easy. The extra effort helps the wider trench last twice as long. A v-trench typically lasts only one season. When you stand back from a finished full trench to view your work, you’ll appreciate the larger, definitive cut.
Follow the lines of the bed boundaries painted by your layout artist. Four inches may seem big, but it only takes a year or two for the trench to degrade. You will need to rebuild trench edging every couple of years.
Here’s a cross section demonstrating a trench edge.
This is not complicated. It doesn’t require a trip to the home improvement store. You don’t have to order anything on line. Just dig! The bottom of the trench is simply dirt. On either side is grass or mulch. All the materials are organic. The lines can be easily expanded or changed with time. Homeowners can dig a few linear feet each day until the edging is complete. Digging these kinds of trenches in a disciplined, determined manner is a great way to contemplate life and its deeper meaning, as long as you don’t overdo it and try to finish all at once. Another option for homeowners is to find a healthy teenager that wants to make some extra money and pay them by the linear foot, so you can work on other projects instead.
Using manufactured edging materials is a way to border beds, but it can go wrong quickly. Anything less than 1/8 inch thick won’t work well or look good. The edging material you use should be so thick it is impossible to bend easily, and must be staked in the ground. It takes just as much labor to correctly install an adequate manufactured edging product than it does to dig a trench edge. Use very high-quality edging for your high-quality landscape.
Strong edging materials should be installed where only ¼ inch is above ground and the rest is buried. Any higher, and people will trip over the edging and the edge will look unnatural. At ¼ inch above ground, the manufactured edging will be high enough so string-trimming equipment can cut off turf grass blades against the high side of the edging material. If installed properly, the edging should be barely visible and should never, ever writhe its way out of the ground.
Some landscape designers use bricks placed on their side or extruded concrete curbing as edging. Bricks can be set in mortar or left loose. Rocks can be used as edging. They need to be placed carefully to look natural. Embedding them partially in the ground helps. Lumber edging is temporary. The lumber will rot in a short amount of time. It looks inferior and unremarkable. Use permanent materials to create a refined edge.
Locate edging just outside the drip line of the shrubs or trees. Any tree mulch ring should be at least six feet in diameter. Bigger is better, and consolidation of several trees in a single large mulch bed is best. I like to start with a large mulch ring (at least twenty feet in diameter), because I know the tree will grow with time. The extra mulch outside the initial drip line can always planted in flowers for added color.
Creating a strong edge along the ground plane between shrub beds and turf areas is an essential part of good landscape design. Be sure to include a requirement to do this in your contract specifications and provide a diagram on your planting details sheet to emphasize the requirement. Show a special line type for edging on plant sheets and add annotation calling out the edging on the plans. Edging provides important detail to the lines of your design.