How to Install Various Garden Edging Types: Step-by-Step Guide

Key Takeaways

• Dig your edging trench to at least 15 cm deep, burying a third to half the edging height below ground level, and lay a compacted 5 cm crushed gravel base before placing anything on top of it.
• Install edging after the sub-base but before the surface material (gravel, paving, turf): this sequence locks the edging between two stable layers and prevents it shifting.
• For stone, brick or paver edging, set the material on the gravel base, level each piece individually, and tamp soil or aggregate firmly against the back face to eliminate air gaps.
• Metal and plastic strip edging needs no form-board: cut a narrow trench to width, push the strip in, and stake every 60 cm.
• A sharp spade-cut edge (no other edging material at all) works as a genuine standalone method: cut vertically to 15 to 20 cm with a half-moon edger, but requires a refresh once or twice a year.

I have installed more garden edging than I can count, and the single most common reason I get called back to fix someone else’s work is the same every time: they didn’t go deep enough. A strip of edging buried 3 or 4 cm into bare soil, with no base underneath, will be lifting by the following spring. I have seen it with metal, plastic, brick, timber – every material going. The material isn’t usually the problem. The install is.

This guide takes you through the full installation process from marking out to back-filling. The six core steps below apply whatever material you have chosen. Underneath, you’ll find the specific adjustments for each edging type.

How to Mark Out Your Edging Line

I want very symmetrical lines, particularly when I’m working for a client, so this step is worth my doing properly, even though it seems like I could skip it and just start cutting in. The problem is that when the line goes wrong at this stage, everything after inherits the wobble. Worst, then you’re chasing your tail – your original line retreats and your garden border gets smaller.

For straight runs, just knock in a stake at each end and run a taut string between them. For curves, lay a hosepipe on the ground and adjust until the shape looks right from a standing distance. Then I mark the line by spreading powdered chalk (but plain flour works a treat!) along the inside edge of the hose. Chalk and flour are better than spray paint for this: they show up clearly on soil and grass, they don’t drift in wind the way paint does, and they wash away if you need to adjust.

I always check my lines from a few angles before cutting anything. A curve that looks smooth from one end can have a flat spot or a kink when you walk around to the side. If something looks off, adjust now, because digging a crooked trench and then trying to straighten it wastes time, weakens the ground and can end ugly at the 15cm depth.

How Deep Should Garden Edging Go?

This is the question I get asked most often, and the answer is more specific than most online guides I’ve read. Dig the trench to at least 15 cm deep. As a rule of thumb, bury a third to half the total height of the edging material below ground level. If the edging is 20 cm tall, at least 7 to 10 cm of that should be underground. For low-profile edging like steel strip, 10 cm of burial depth is the practical minimum, because anything shallower will not resist pressure from grass roots, foot traffic, or even frost movement.

Solid Edging Needs a Base

At the bottom of the trench, tamp a 5 cm base of compacted crushed gravel (10mm or 20mm gravel works – basically anything angular that packs down a bit flat). This base does two jobs: it drains water away from the bottom of the edging so the soil underneath doesn’t become a mud layer, and it gives the edging something rigid to sit on. Without it, the edging is resting on bare soil that expands and contracts with moisture and temperature. That movement is what lifts edging out of the ground over winter.

The 5cm gravel base is the secret that separates edging that lasts from edging that needs resetting every year or so. In my experience, about eight out of ten edging failures I have seen on other people’s jobs come down to no base, or a base that was never compacted. I lay it, tamp it flat, check it with a spirit level, and bang the edging on top of it – everything is dapper from that point.

Why the Install Sequence Matters

Here is the rule most DIY guides skip, and it matters more than people think. If you are installing edging alongside a path, patio, or any paved surface, the correct sequence is: sub-base first, edging second, surface material last. That means the gravel or hardcore base for the path goes down, the edging gets set into or against it while it is still exposed, and then the surface stone, slabs, or gravel gets laid up to the edging on one side while soil or turf meets it on the other.

Getting this sequence wrong, typically by laying the surface first and then trying to bolt edging onto the side of it, creates two problems. First, you cannot compact the base properly against the edging because the surface is already in the way. Second, the edging has nothing to brace against on the paved side, so it will shift outward under lateral pressure. I have pulled up and relaid edging on jobs where the previous installer put it in last, and in every case the base underneath had a gap between the edging and the compacted sub-base. That gap is where movement starts.

If you are edging a standalone bed with no adjacent paving, the sequence is simpler: trench, gravel base, edging, backfill. But the principle is the same. The edging sits on a prepared, compacted layer, and the material on both sides of it gets packed tight after the edging is in position, not before.

What You Need Before You Start

The tools are simple. Most of them are already in your shed, and the one you might not have, a half-moon edger, costs under fifteen pounds and is worth every penny.

For timber edging specifically, add a drill with a screwdriver bit, galvanised corner braces and mending plates, and galvanised screws. For concrete-reinforced edging, add 1×4 form boards, double-head nails (so they pull cleanly after curing), and a crowbar or length of 2×4 to steady stakes while nailing.

Materials

Whatever edging type you have chosen, plus enough 10mm or 20mm crushed gravel to lay a 5cm base along the full length of the trench.

Step-By-Step Guide

These six steps cover the basic process for setting an edge. However, because each material can have their quirks, I follow this section with a list of how to handle each edging material type, underneath.

Step 1: Mark Out Your Line

Set up your string line for straight runs, or lay a hosepipe for curves, and mark it with chalk or flour, as per the marking out section above.

Step 2: Dig the Trench

Use a half-moon edger or sharp spade to cut a clean vertical line along your marked edge. Dig to a depth of 15 to 20cm and remove the wedge of sod. Cut sharply and vertically: a clean cut this deep severs creeping grass rhizomes below where they travel and discourages regrowth into the bed. If you dig out any turf, turn it upside down and leave it somewhere for six to nine months to rot into reusable soil.

Step 3: Lay the Gravel Base

Spread 5cm of crushed gravel (10mm or 20mm) along the bottom of the trench. Compact it flat and check it with a spirit level. This base is what stops the edging sinking, shifting, or lifting over winter.

Step 4: Set the Edging in Position

Place your edging material on the gravel base, tight against the cut turf edge. Use a tape measure to confirm you have enough material for the full run, and aim to position any joins along a straight stretch rather than on a corner. Level each piece as you go, checking both along the length and across the width.

Step 5: Backfill and Secure

Tamp soil, soil or aggregate firmly against the back of the edging to eliminate air gaps. For metal or plastic strip, stake every 60 cm along the outside (closer on curves). For masonry, pack material against both faces and check level again after tamping.

Step 6: Connect Joins

Where one length of edging meets the next, use the connector or joining plate supplied with your system. Fit these as you go rather than trying to retrofit them at the end. A screwdriver or small spanner helps seat the connector snugly and stops the joint flexing apart under soil movement later.

Pro Tip: If you have installed a mowing strip, this is also a good point to run a mower over it on its lowest setting and check the edging clears the blade cleanly along the full run, before you consider the job finished.

How to Install Stone, Brick or Paver Edging

Stone, brick, and pavers all follow the same basic method. The differences are in the detail.

Set each piece on the gravel base and tap it into position with a mallet. Check level as you go, both along the length (so the top reads as a consistent line) and across the width (so the piece isn’t tilting inward or outward). Tamp soil, compost, or gravel firmly against the back face of each piece to eliminate air gaps. Air gaps left behind edging is where grass roots find a way through and also where frost has room to lever the edging out.

Soldier Course for Bricks

A soldier course is bricks set on end in the trench, edges butting tight against each other, with joints filled with sand or dry mortar. This is the standard edge for a path, patio, or driveway border, and it is as stable as any edging method gets when done properly.

For sand-laid paving, the soldier course can sit in a trench with tamped, well-drained soil packed around it. For mortared paving, or in areas where the ground freezes hard over winter, set the soldier course in mortar on a concrete base. The mortar joint is not optional in these conditions: a sand-set soldier course in a frost zone will heave and separate within two or three winters.

Fill joints between bricks with sand or dry mortar depending on the setting method. Dry mortar joints are stronger but harder to redo if a brick needs replacing later. Sand joints are weaker but allow individual bricks to be lifted and reset, which is a genuine advantage if you aren’t entirely sure and the bed layout may be changed in future.

Cut Stone and Pavers

Cut stone and pavers follow the same method as brick but with one extra consideration: the pieces are usually heavier and less uniform, so the gravel base needs to be properly levelled before each piece goes down rather than relying on the mallet to tap everything flat. A paver that rocks on its base will crack under foot traffic. I always put in the time to get the base right under each piece individually.

Fieldstone and Cobbles

Fieldstone and random-shape cobbles do not give you the tight-butting joints that cut stone or brick do, but the gaps between pieces form part of the look. Look to fill them with gravel, soil, or creeping plants depending on the style. For stability, try pick stones with at least one reasonably flat face and set that face down, because stones without a flat face will eventually roll under pressure and end up in the bed or path. If you are edging a formal feature, fieldstone is the wrong material; if you are edging a cottage-style border, it should look right.

How to Install Metal or Plastic Strip Edging

Metal and plastic strip edging is designed to be the simplest to install of any material. No form-board, no mortar, no levelling individual pieces. The trench to dig is narrower (just wide enough for the strip plus a finger’s width on each side), the strip goes in, and the stakes hold it.

Cut the trench to the depth of the strip plus 5 cm for the gravel base. Push the strip into the trench so the top edge sits at whatever height you want above ground level. For a mowing strip, that means no more than 2.5cm above turf level, so that mower can safely pass over it. For a bed edge, anything up to 5cm high is fine. I stake every 60cm along the outside of the strip, but more often for curves, then backfill the inside of the trench and tamp firm.

How to Cut Clean Corners in Metal Strip

Many metal edging kits don’t include corner pieces, yet overlapping two strips at a right angle gives a sloppy, unstable joint. The proper method is a fold.

At the point where you need the corner, mark the strip and cut into it from the top edge, downward, to exactly halfway through its height. Do not cut all the way through. Bend the strip on the cut line, folding it back onto itself to make a clean crease. Then open the fold back out to 90 degrees. The cut faces lock against each other and the crease holds the angle. Secure with a stake on the outside of the corner, tight against the fold, and backfill. This gives a crisp, mitred corner that holds its shape under pressure.

Joining Straight Runs

Most metal edging systems use a connector or joining plate that overlaps or bolts sections together so the line reads as continuous rather than a visible seam. Again, it’s best to fit these as you go rather than trying to retrofit them after it’s all staked, and where possible, position joins along straight stretches rather than at a corner or bend.

Curves

Plastic and metal strip edging both work well for curves and are among the most widely used options between lawns and planting areas for exactly this reason. Push and stake the strip gradually along your hosepipe-marked line as you go, rather than forcing it around a tight radius in one go. For a sharper curve or a genuine right-angle corner, use the fold technique above instead of bending the strip past its comfortable radius, which can kink or crease it in the wrong place.

How to Install Concrete Edging

For how to install concrete edging with poured cement, dig a trench to the desired width and ensure it is level. Install forms on each side of the trench, staked at intervals with double-head nails so they pull cleanly after curing. Pour concrete to the top of the forms, strike off and float the concrete. Let it cure for a week before removing the forms.

How to Install Timber Edging

I love timber edging – it looks warm and natural – plus, when the right timber is used it lasts well. Choosing the wrong timber leads to rot from underneath within three to five years, and then everything set against it destabilises. Nightmare to fix.

The right timber for ground-contact edging is a species with natural decay resistance: oak, sweet chestnut, or larch in the UK. Pressure-treated softwood is a common alternative and it does extend the lifespan, but in my experience it still cracks and deteriorates faster than hardwood, particularly where the end-grain sits in damp soil. I would always recommend a naturally durable type where the budget allows.

Pro Tip: A dropsaw would be the ideal wish-list tool for the next task – It will get you the 45° cuts perfectly but also allow you to have square and bits for the next step.

Cut lengths to fit, with 45° mitre cuts at corners. Lay in the trench on the gravel base, connect straight joints with galvanised mending plates screwed to the inside face, and fix corners with galvanised corner braces. Backfill and tamp. For runs longer than about 2 metres, or anywhere the timber will take lateral pressure from soil or foot traffic, drive galvanised stakes or lengths of number 3 rebar into the ground on the outside face at 60 cm intervals and fix the timber to them with screws.

Pro Tip: The rebar is stronger and cheaper than pre-fabricated timber stakes, you will just need a grinder or a good hacksaw to cut them to length.

How to Cut a Sharp Spade Edge

This is the method that gets overlooked in most edging guides – possibly because there’s nothing to sell – yet it is a very effective alternative to any physical material, provided you are up for a bit of maintenance once or twice a year.

The tool is a half-moon edger, not a flat spade. The curved blade is designed to cut a clean vertical line into turf, and it does the job better than any improvised alternative. Push the blade vertically into the soil to a depth of 15 to 20 cm, working along the line you marked with chalk or string. Cut sharply and vertically. The depth matters: a cut this deep severs the horizontal rhizomes of creeping grasses (couch, bent, creeping fescue) at a level below where they travel. This discourages them from growing back across the line and into the bed. A shallow 5cm nick with a spade does not do this, so the grass will be back across the line within weeks.

Remove the wedge of turf cleanly and rake the exposed edge. The result is a sharp, defined line between lawn and bed, with no material in the way of a mower or a strimmer.

The one thing to remember is that this edge is not set-and-forget. Grass regrows, soil slumps, and the line softens over a season. Plan to re-cut in early spring and again in late summer if the grass is vigorous. Each re-cut takes a fraction of the time the first cut does, because you are refreshing an existing line rather than cutting a new one. If the idea of seasonal maintenance puts you off, go with a physical material. If you would rather spend nothing and do a twenty-minute pass along the beds twice a year, this is the method.

One design note, from the forums and from my own observation: gentle curves are more forgiving than perfect straight lines for spade-cut edges. A straight line shows every slight wobble. A gentle curve tolerates small variances and often looks less DIY in a residential garden.

Common Installation Mistakes

Every one of these comes from jobs I have seen, either my own early work or other people’s installs I have been asked to fix.

Too shallow. The single most common failure. Edging buried 3 to 5cm into bare soil, with no gravel base, will lift or shift after the first hard frost or a wet winter. The fix is the 15cm trench and 5cm gravel base described above. There is no shortcut that works.

No base at all. Edging set directly onto soil, even at the right depth, rests on a surface that moves. Clay soils expand when wet and shrink when dry. Sandy soils compact unevenly. The gravel base gives the edging a stable, draining platform. Without it, movement is pretty much guaranteed.

Wrong sequence. Installing edging after the surface material means the edging has nothing to brace against. The surface should go in after the edging is set and back-filled.

Stakes too far apart. Metal and plastic strip edging needs a stake every 60cm at minimum. Most kit instructions say every 90 cm or more. In my experience, the kit spacing is too wide for anything except dead-straight runs on firm, level ground. On curves, closer to 40cm.

Plastic in frost-prone areas. Plastic strip edging becomes brittle in cold weather and cracks under the pressure of frost heave. If your site gets regular hard frosts, steel or stone is a better choice. Plastic will work for a couple of seasons and then need replacing. That is not necessarily a deal-breaker for a budget install, but it is worth knowing up front rather than being surprised.

Timber without ground-contact treatment. Untreated softwood in direct soil contact rots from underneath. By the time you see the rot on the surface, the bottom edge has already lost its structural integrity. Use a naturally durable species, or minimum pressure-treated timber.

If you have fitted edging yourself, how did the job go? Which part turned out to be the fiddly bit? Let us know in the comments.

FAQs

Can I install garden edging without digging a trench?

Installing garden edging without a trench will not work long term. While some no-dig plastic kits are designed to push directly into the soil surface, they only work for light decorative edging in soft ground, but they do not resist lateral pressure from grass, foot traffic, or frost. For anything that needs to stay put longer than one season, dig the trench and lay the base. The extra hour of digging saves you resetting the edging every spring.

Do I need a gravel base for timber edging?

Yes. Timber sitting directly on soil absorbs moisture from underneath and rots faster. A 5cm gravel base drains water away from the bottom of the timber and extends its lifespan measurably. I have seen oak sleeper edging last over fifteen years on a proper gravel base, and pressure-treated softwood fail within four years without any.

How do I stop grass growing through the edging?

To stop grass growing through the edging, bury the it deep enough that its base sits below the rhizome zone of the grass species in your lawn. For most British creeping grasses (couch, bent, creeping fescue), 10cm of buried depth is the minimum. Combined with a 5cm gravel base, this puts the bottom of the edging at 15cm below ground level, which is below where most rhizomes travel.

Can metal edging be bent to follow a curve?

Yes, metal edging be bent to follow a curve. Plastic and metal strip edging both work well for curves and metal is my go-to option between lawns and planting areas for exactly this reason. For a sharper curve or a genuine right-angle corner, use the fold technique described above instead of bending the strip past its comfortable limit.

What is the easiest garden edging to install?

Metal or plastic strip edging is the easiest and fastest to install: one small trench, push in, stake, backfill. A spade-cut edge is the cheapest (free, in fact) but needs refreshing every season.

How do I keep my mowing strip level with the mower?

After Step 6, run your mower over the finished strip on its lowest cutting setting and check it clears the edging cleanly along the whole run before you consider the job finished. If the mower catches anywhere, that section needs tamping down slightly or the edging height adjusting.