Landscape edging or curbing can put the finishing touch on a landscape project, and concrete makes it very permanent. A clean concrete edge keeps grass out of your beds, holds mulch in place and gives the whole yard a neat, cared-for look.
The good news: you can make your own concrete landscape edging with bagged concrete mix, a few form boards and some careful prep. The honest news: it is real concrete work, with real safety rules. Here’s how to plan it, pour it and cure it, step by step.
Why Concrete Edging?
Edging does more than look tidy. The UF/IFAS Florida-Friendly Landscaping Program says edging can help highlight shrubs and trees, contain mulch, keep plants from spreading and reduce mowing time. For a durable border, it suggests stone, brick, concrete, plastic or aluminum, and it notes that all wood edging needs replacing every few years.
K-State Research and Extension (a Johnson County Master Gardener fact sheet) calls cement curbing attractive and durable and says it provides a mowing strip, so your mower wheels can run right along the edge. The same sheet gives the trade-off: its permanence does not allow for easy expansion of the gardens in the future. Pick your lines carefully, because you will live with them.
Machine Curbing Or A DIY Formed Edge?
There are two kinds of concrete edging, and it helps to know which one you are building.
Continuous curbing is the smooth, unbroken curb poured in place by a machine. Illinois Extension describes it as continuous concrete edging poured by special machines, which resists cracking thanks to added polyolefin fibers. K-State’s fact sheet says cement curbing must be professionally installed (it does not discuss a hand-formed edge). If that is the look you want, get a couple of local quotes.
A formed edge is the DIY version. You dig a shallow trench, set form boards on each side, fill it with concrete mix and finish the top. Quikrete’s data sheet for its Concrete Mix lists curbs among the uses for the product, for pours 2 inches thick or more. That’s the project this guide walks through.
Before You Dig
Lay out the line. K-State suggests outlining the edge with a rubber hose or heavy rope first. For curves, adjust until you have a large, smooth curve that will be easy to mow, and leave room for your plants to grow to their mature size.
Call 811. It’s fast, easy and free, and the utility company will come out in a matter of days and mark underground wires and pipes for you, according to UF/IFAS Gardening Solutions. Do this before the first shovel goes in.
Think about the plants next to it. Concrete can change the soil beside it. UF/IFAS says building materials in the home landscape, including concrete and stucco, may create alkaline conditions. Larry Figart, a UF/IFAS Extension Duval County agent, writes that he has often seen soil pH change dramatically near a street, sidewalk or home foundation. UF/IFAS adds that a few acid-loving plants, including azalea, blueberry and gardenia, will not do well in soils with a pH greater than 5.5, while most common landscape plants tolerate a wide range of pH. If you plan to grow acid lovers along the new edge, test the soil first. UF/IFAS says the University of Florida Extension Soil Testing Laboratory can test for pH.
What You’ll Need
- A garden hose or rope to mark the line
- A flat spade and a tamper to firm the trench bottom
- Form boards (flexible strips for curves, straight boards for straight runs), plus stakes and screws or nails
- Bagged concrete mix, a wheelbarrow or mixing tub, a hoe and clean water
- A short straight board for striking off, a trowel or float, an edging tool and a grooving tool
- Plastic sheeting, burlap or a garden sprinkler for curing
- Safety gear: waterproof gloves (nitrile or butyl), waterproof boots, eye protection, a dust mask and kneepads
How To Make Concrete Landscape Edging, Step By Step
Step 1: Dig The Trench
The mix directions start with staking out the area and removing sod or soil to the desired depth. Extension sources don’t give a standard size for a DIY curb, so size it to your yard. For a mowing strip, keep the top of the edge level with the lawn. As a reference point, Illinois Extension says a hand-cut edge 4 inches deep and wide can easily contain bluegrass. Remember that the concrete itself needs to be at least 2 inches thick, per the product directions.
Step 2: Firm The Base
The directions say to tamp and compact the sub-base until firm. A University of Wisconsin Extension concrete specification (written for farm pads, but the principle carries over) says concrete shall not be placed on mud, dried earth, uncompacted fill, frozen soil or in standing water. Take the time to get the trench bottom firm and even.
Step 3: Set And Stake The Forms
The directions say to nail and stake forms securely in place. The Wisconsin specification asks for forms that are “substantial and unyielding,” so the finished concrete keeps its shape. Use straight boards on straight runs and a thin, flexible strip on curves, with plenty of stakes on the outside so the forms don’t bow when the concrete goes in. Check the top of the forms with a level as you go, because the top of the form becomes the top of your edge.
Step 4: Figure Out How Much Mix You Need
The data sheet says an 80-pound bag of the mix yields about 0.60 cubic foot. As an example, an edge 6 inches wide and 4 inches deep uses about 0.17 cubic foot per running foot, so one 80-pound bag fills a little over 3.5 feet of it. A 50-foot border would take roughly 14 bags. Do the math for your own size, and buy a bag or two extra.
Step 5: Mix The Concrete
The directions say the mix can be made by hand: for each 80-pound bag, add about 6 pints of clean water to start, then work it with a shovel, rake or hoe, adding water as needed until it reaches a stiff, moldable consistency. The final water content should be about 6 to 9 pints per 80-pound bag. Make sure there are no dry pockets, and don’t leave standing puddles of water. Other mixes have their own directions, so follow the label on the bag you buy.
Step 6: Pour, Strike Off And Edge
The bag’s directions: dampen the ground before you pour, but don’t leave puddles. Fill the forms to their full depth and work continuously from one end to the other, because partial-depth fills could lead to cold joints. Then strike off right away, moving a straight board back and forth along the top of the forms with a sawing motion to smooth the surface. Run an edging tool or trowel along the forms to compact the edges.
Step 7: Cut Control Joints
Control joints are shallow grooves that give concrete a planned place to crack. For slabs, the directions say to cut 1-inch-deep control joints every 6 to 8 feet with a grooving tool. Its sheet gives no separate spacing for a narrow edge, so treat that as a starting point and space them evenly along your run.
Step 8: Finish The Surface
The directions say to let the concrete stiffen slightly and wait until all water has evaporated from the surface before troweling or brushing on a broom finish. It also says not to overwork the material. Choose a troweled or broom finish for the look you want.
Step 9: Cure It Properly
Don’t skip this step. The directions call curing one of the most important steps in concrete construction and says it should start as soon as possible and continue for 5 days in warm weather at 70°F or higher, or 7 days at 50 to 70°F. Its options include covering the concrete with wet burlap or plastic sheeting, keeping it wet with a lawn sprinkler, or using a cure-and-seal product. It also says to protect the concrete from freezing during the first 48 hours.
Heat matters too. The Wisconsin specification says that in hot weather (generally above 80°F, especially with low humidity and wind) the surface should not be allowed to dry out, and that in extreme conditions it may be necessary to pour in the late afternoon or evening.
Step 10: Remove The Forms And Backfill
The Wisconsin specification says forms may come off when the concrete is sufficiently cured that it will not be damaged. Pull the stakes, slide the forms away gently, then backfill soil or sod against both sides of the new edge and top-dress your beds with mulch.
Stay Safe With Wet Concrete
This part isn’t optional. OSHA says wet portland cement can damage the skin because it is caustic, abrasive and absorbs moisture, and it can cause caustic burns, sometimes called cement burns. OSHA warns that cement burns may not cause immediate pain, can get worse even after contact has ended, and that anyone with a cement burn should see a healthcare professional right away.
- Gloves: OSHA says butyl or nitrile gloves are frequently recommended for caustic materials, rather than cotton or leather gloves. Use well-fitting gloves and keep wet cement from getting inside them.
- Boots and clothes: wear waterproof boots high enough to keep wet cement out, and change out of clothing that gets soaked with it.
- Knees: when kneeling on wet concrete, OSHA says to use waterproof kneepads or dry kneeboards.
- Eyes and lungs: OSHA says to wear proper eye protection. The product sheet adds a mask and warns that prolonged or repeated inhalation of the dust may cause lung damage or cancer.
- If it gets on your skin: OSHA says to wash with clean, cool water and a pH-neutral or slightly acidic soap, and not to use lanolin, petroleum jelly or other skin-softening products.
The label also says to keep the product out of reach of children, so keep kids away from the mixing area and the fresh pour.
Want More Edging Ideas?
Concrete is only one option. Brick, stone, metal, wood and recycled materials all make good borders, each with its own look and upkeep. See our roundup of garden border ideas for more inspiration.
Have you poured your own concrete edging? Tell us how it turned out, and share your best tip for a clean curve.
Frequently Asked Questions
Can I make concrete landscape edging myself?
Yes, if you build a formed edge. The data sheet for a bagged concrete mix lists curbs among its uses, for pours 2 inches thick or more. Continuous curbing is different: Illinois Extension describes continuous concrete edging as poured by special machines, and K-State’s Master Gardener fact sheet says cement curbing must be professionally installed.
How long does concrete edging need to cure?
The data sheet for the bagged concrete mix says curing should start as soon as possible and continue for 5 days in warm weather at 70°F or higher, or 7 days at 50 to 70°F. Keep the surface moist with wet burlap, plastic sheeting or a lawn sprinkler, or use a cure-and-seal product, and protect it from freezing during the first 48 hours.
Do I need to call 811 before digging a trench for edging?
Yes. UF/IFAS says to call 811 before you dig. It says the service is fast, easy and free, and that your utility company will come out in a matter of days and mark underground wires and pipes for you. Make the call before you start digging, since even a shallow edging trench goes into the ground.
Will concrete edging affect the plants next to it?
It can raise the soil pH. UF/IFAS says building materials such as concrete and stucco may create alkaline conditions, and a UF/IFAS Duval County agent has seen soil pH change dramatically near sidewalks and foundations. Most landscape plants tolerate a wide pH range, but UF/IFAS says azalea, blueberry and gardenia will not do well above pH 5.5.
How do I protect my skin when working with concrete?
Keep wet concrete off your skin. OSHA says wet portland cement is caustic and can cause burns that may not hurt right away. It says butyl or nitrile gloves are frequently recommended over cotton or leather, and it advises waterproof boots, waterproof kneepads or dry kneeboards, and eye protection. Wash any concrete off your skin with clean, cool water and a pH-neutral or slightly acidic soap.