By Caleb MorganUpdated November 2026
The best landscape edging to keep grass out is a rigid barrier set low and firm along the edge of your bed, buried deep enough that grass roots can’t travel under or over it. Most homeowners get the best results with a metal, steel or heavy plastic strip that sits flush with the soil line. This guide covers how to pick the right material, how to install it, and what usually goes wrong.
Choose a Barrier That Blocks Roots, Not Just Grass Blades
Grass spreads mainly by underground runners called rhizomes and stolons. A barrier that only stands a couple of inches above the soil will stop the blades from creeping in, but roots will push underneath it. Look for edging that reaches at least 4 to 6 inches deep when installed. Manufacturers of steel and aluminum strip edging typically specify a burial depth in this range, and the deeper the barrier, the longer it holds.
Material matters too. Steel and aluminum resist bending and rarely crack, which keeps the line straight over time. Heavy-gauge plastic works well in softer soils and is easier to cut. Stone and paver edging can work, but only if the pieces are set in a continuous bed of mortar or compacted base with no gaps for roots to exploit.
How to Install Grass-Blocking Edging Step by Step
Installation determines performance more than the product does. Follow these steps for a barrier that stays put and keeps grass out.
- Mark the bed line with a garden hose or spray paint. Smooth, sweeping curves are easier for the edging to follow and look cleaner than tight bends.
- Dig a trench along the line about 2 to 3 inches wide and as deep as the edging’s full height, plus a half inch so the top sits slightly below the lawn surface.
- Set the edging in the trench with the grass side facing the lawn. Check that the top edge is level with or just under the turf.
- Secure it with the stakes or spikes the product calls for, spaced roughly every 12 to 18 inches. Drive them in so the stake heads sit below the top edge.
- Backfill the trench with soil, tamping it firmly against the barrier on both sides to eliminate gaps where grass can sneak through.
Match the Edging to Your Soil and Layout
Heavy clay soil expands and contracts with moisture, which can push thin edging out of line. In clay, choose thicker steel or aluminum and check the alignment after the first wet season. Sandy soil shifts more easily, so deeper stakes and a firm backfill matter more. For tight curves, flexible plastic or steel strips bend better than rigid stone. For straight runs along a walkway, a continuous metal edge gives the cleanest result.
Watch for Gaps at Joints
Where two lengths meet, a small gap or overlap can let runners through. Overlap the ends by an inch or two, or use the manufacturer’s connector if one is provided. Check these seams each spring, since frost and mowing can slowly open them.
Common Mistakes That Let Grass Back In
- Setting the barrier too shallow. A few inches of depth is rarely enough for vigorous lawn grasses like Bermuda or zoysia.
- Leaving the top edge proud of the soil, which causes mower blades to scalp the edge and loosens the stakes.
- Skipping backfill compaction, leaving air pockets that roots can travel through.
- Using too few stakes, so the line bows outward under the weight of mulch or soil.
- Ignoring the line for years. Pulling back runners early is far easier than digging out an established mat.
Recommended gear
A sharp half-moon edger helps you keep the cut clean along the barrier once it’s in place, which prevents grass from creeping over the top.
A string trimmer or edging attachment lets you maintain the lawn side without damaging the barrier with a mower.
A tamper or hand tamper makes backfilling firm and even, which closes the gaps roots would otherwise use.
For a broader look at materials, see Best Landscape Edging for Mulch and Grass Control: 5 Edging Compared and 7 Best Grass Barrier Landscape Edging Options of 2026. If you’re working with a metal option, Best Steel Landscape Edging: How to Choose and Install for Clean Lines (2026) covers installation details in depth.
FAQ
How deep should landscape edging go to stop grass?
Most grass-blocking edging should reach 4 to 6 inches below the soil surface. Shallower barriers let rhizomes pass underneath, especially with aggressive warm-season grasses.
Will plastic edging keep grass out as well as metal?
Heavy-gauge plastic can work well in loose soil if buried deeply and staked securely. Metal tends to hold its line longer in clay or under heavy root pressure.
Do I need to replace edging every few years?
Quality steel or aluminum often lasts many years, while plastic can become brittle with sun exposure. Inspect the line each spring and replace sections that have cracked, bowed, or opened at the joints.
Conclusion
The best landscape edging to keep grass out is one that goes deep, sits firm, and has no gaps at the joints. Choose a material that suits your soil, install it below the turf line, and backfill carefully. A quick spring check will keep your beds clean all season.
Ready to choose one?
About Caleb Morgan
Caleb Morgan is part of our editorial team and reviews and edits our lawn edging & trimming guides, checking product details against manufacturer specifications and owner feedback.
