How to Create a Trench for Landscape Edging

Creating a trench for landscape edging is a fundamental step in defining garden beds, pathways, and lawn borders. Not only does a well-executed trench provide a neat and clean division between different areas of your yard, but it also helps prevent the spread of grass or weeds into flower beds and keeps mulch or decorative stones in place. Whether you’re installing plastic, metal, or stone edging, digging the proper trench is essential for durability and aesthetics.

In this article, we will guide you through the step-by-step process of creating a trench for landscape edging. From planning and marking to digging and final preparations, you’ll learn everything you need to know to create a professional-looking edge that enhances your outdoor space.

Why Create a Trench for Landscape Edging?

Before diving into the how-to, it’s helpful to understand why trenches are necessary when installing landscape edging:

Stability: A trench anchors the edging material firmly in place, preventing it from shifting or tipping over as soil settles or during heavy rain.
Clean Lines: Trenches allow you to bury the edge slightly beneath the surface, providing crisp, clean lines that improve the overall look.
Weed Control: By creating a physical barrier underground, trenches help keep grass and weeds from creeping into flower beds.
Longevity: Properly installed edging with trenches tends to last longer without maintenance as the soil supports the edging material.

Tools and Materials Needed

Before starting your project, gather the necessary tools and materials to make the process smoother.

Tools

Measuring tape: To measure lengths accurately.
Garden hose or string line: For marking your desired path.
Spray paint or marking chalk: To outline the trench location.
Shovel or spade: For digging the trench.
Hand trowel or trenching tool: For more precise digging.
Gloves: To protect your hands.
Wheelbarrow or bucket: To remove excess soil.
Level (optional): To ensure even depth.

Materials

Landscape edging material (plastic, metal, stone, brick, etc.)
Stakes (optional) to hold string lines
Sand or gravel (for base leveling)
Mulch or soil (to cover edges after installation)

Step 1: Plan Your Landscape Edging

Every successful project starts with planning. Before you dig any trenches:

Define the Area: Decide where you want your landscape edging. It could be around flower beds, along walkways, garden paths, driveways, or lawn borders.
Determine Shape and Length: Use a garden hose laid on the ground to visualize curves or straight edges. Adjust until you’re happy with the shape.
Measure Length: Use measuring tape to determine how much edging material you’ll need.
Check for Utilities: If planting near structures or existing underground utilities like irrigation lines, call your local utility locating service to avoid damage.
Choose Edging Material: Different materials require different trench dimensions (e.g., metal may require narrower trenches than stone).

Step 2: Mark Your Trench

Once your plan is finalized:

Use spray paint or marking chalk to outline your desired edge on the ground.
Place stakes on either side of the line and tie string between them if you want a perfectly straight edge.
Double-check measurements and alignment before starting to dig—adjust markings if needed.

Step 3: Determine Trench Dimensions

The size of your trench depends largely on the type of edging you plan to install:

Plastic or metal edging: Typically requires a trench about 4-6 inches deep and 4 inches wide.
Brick or paver edging: Requires deeper trenches—usually about 6-8 inches deep and wide enough for bricks plus some extra room for sand leveling.
Stone edging: Similar to brick but may require even more depth depending on stone size; generally 6–8 inches deep.

Keep in mind that at least half of your edging should be buried below ground level for stability.

Step 4: Start Digging Your Trench

With markings done and measurements set:

Begin digging along your marked line using a sharp spade or trenching shovel.
Remove sod carefully by slicing vertically along edges before lifting it out; this allows you to reuse sod later if desired.
Dig to your predetermined depth and width — use a level occasionally to ensure consistent depth along the entire length.
Scoop out soil into a wheelbarrow or bucket as you go; avoid piling soil on adjacent planting areas.
For curved sections, dig carefully following hose or chalk line contours for smooth curves rather than jagged edges.

Step 5: Prepare Trench Base

The base of your trench must be firm and level:

Remove loose debris such as rocks or roots from bottom of trench.
Add a layer of sand or fine gravel (about 1 inch thick) if installing brick, paver, or stone edging — this acts as bedding material that improves drainage and provides an even surface.
Use a tamper or flat object to compact and level the base gently.

For plastic or metal edging, this step can sometimes be skipped unless specified by manufacturer instructions.

Step 6: Install Landscape Edging

After preparing your trench base:

Position your edging material into the trench making sure it sits flush with surrounding soil surface — about half buried below grade.
For flexible plastic/metal edging, bend as necessary along curves; use stakes supplied with product to anchor securely in place on outer side of curve.
For rigid materials like bricks/stones, place them tightly side by side; check vertical alignment using a level periodically.
Tap bricks/stones gently with rubber mallet to adjust height evenly across length.

Step 7: Backfill Soil and Finish

Once your edging is in place:

Backfill with remaining soil removed during digging around both sides of edging material, firming soil gently by hand to eliminate air pockets.
Tamp down soil lightly with foot pressure for stability but avoid heavy compaction that could damage edging.
Water area well after backfilling; this helps settle soil further around edging base.
Replace any removed sod exactly over edges if desired; water regularly until sod re-establishes roots properly.
Add mulch inside beds up against edging line for neat appearance and additional weed control benefits.

Tips for Successful Trench Creation

Work in manageable sections rather than trying entire length at once.
Keep blade sharp on shovels/spades for easier cutting through turf.
Wear gloves to protect hands from blisters or cuts.
Avoid digging on extremely wet days when soil is heavy and sticky.
Maintain consistent depth throughout trench—variations cause uneven edges.
When working on slopes, dig deeper end slightly higher so top edge remains level visually.

Troubleshooting Common Issues

Uneven Edges

Use a string line at top edge height as reference while digging; regularly check with level during installation phase to prevent unevenness due to settling soil.

Edging Shifts Over Time

Ensure proper depth; stake flexible edgings on curves tightly; compact backfill thoroughly; avoid excessive foot traffic directly on fresh installations initially.

Difficulty Digging Hard Soil

Water area thoroughly a day before digging; this softens soil making it easier to work; consider renting a power trencher for large projects with tough ground conditions.

Conclusion

Creating a well-defined trench is key when installing landscape edging that looks great and lasts long. With careful planning, correct tools, and attention to detail during digging and installation phases, you can transform your garden beds and pathways into stunning features that enhance curb appeal and maintain order in your outdoor space.

Whether you’re working with plastic strips for flexible curves or sturdy brick borders for classic looks, following these steps will help make your landscaping project successful from start to finish. Happy gardening!