How to Install Plastic Garden Edging? | Done Right in a Weekend

Installing plastic garden edging correctly means digging a consistent trench and keeping the top edge just barely above the soil line, so it blocks turf without becoming a trip hazard or mower target.

A sharp lawn edge makes the difference between a landscape that looks professional and one that looks like someone just dropped a roll of plastic on the ground. The problem is that most DIY tutorials skip the details that actually matter: how deep to set it, how many stakes to use, and how to handle curves. If you are looking for the right tools and materials first, our tested roundup of the best plastic garden edging can point you to a product worth the effort. Once you have the edging, here is the install sequence that works.

Mark the Border and Dig the Trench

Lay out your border with spray paint, garden rope, or a hose so you can step back and see the shape before you dig. Measure the full run after you have the line set—this confirms how much edging you actually need. Dig a trench along the line; the most common depth guidance is 3 to 4 inches, though some manufacturer instructions say the trench should be the edging height plus about an inch. Keep the trench floor flat so the edging sits at a consistent height.

One key detail: remove any grass, roots, or debris from the trench before setting the edging. If you skip this, the edging rides on lumps and the border will look wavy by midseason.

Set the Edging at the Right Height

Place the edging in the trench so only about 1/4 to 1/2 inch remains above ground level. That small exposed lip is enough to stop creeping grass from crossing the border, but it is low enough that a lawn mower can pass over without striking the edge and low enough to avoid being a trip hazard. Some product designs have anchoring tabs; orient those toward the planting bed, not the lawn side, so the stakes pull the edging against the soil.

For curved sections, place stakes closer together than on straight runs. Plastic edging does not bend easily around corners, so tighter stake spacing and occasional shaping by hand are necessary to hold the curve.

Join Pieces and Stake the Run

If your run needs multiple lengths of edging, join them with the manufacturer’s coupler or connector. One common method is to slide the coupler halfway into the top channel of the first strip, pinch the edging to hold it, then fit the second strip and push the pieces tightly together so the seam is minimal. Cut the edging to length at the midpoint between anchoring tabs using snips or a fine-tooth saw.

Staking guidance varies by product: some manufacturers recommend a spike every 10 tabs, while broader how-to guides suggest spacing stakes every 12 to 18 inches on straight runs. The safe answer is to use more stakes than you think you need and add extras wherever the edging feels loose. Use the stakes that came with the edging or buy additional ones if the product sells them separately.

Backfill, Compact, and Settle

Push the excavated soil back into the trench, pressing it firmly against both sides of the edging. Compact the soil by stomping it with your feet or using a hand tamp—loose backfill is the main reason edging works its way up over time. Water the border lightly after backfilling to help the soil settle and lock the edging in place.

The most common mistakes happen in this step: skipping the compaction entirely, and failing to account for the curl the edging developed while packaged. If the edging still wants to spring out of shape after backfilling, it needs more stakes or deeper compaction right now.