Key Takeaways
- Garden edging comes in three functional types: a kerb (a raised lip) holds back vehicles and raised soil, a flush edging defines beds and paths, and a mowing strip lets a mower pass straight over the lawn edge.
- The garden edging materials that last longest are steel and stone or brick set on a proper base; plastic strip edging goes brittle in sunlight and pops out of the ground within 2 to 5 years.
- Edging should be buried a third to a half of the edging’s height (10 to 15cm minimum) on a compacted crushed gravel base at least 5cm deep, or expect maintenance every spring.
- To stop grass creeping into beds, the edging barrier needs to sit at least 10cm deep, below the zone where creeping grass roots travel sideways.
- Not every garden feature needs edging: a well-built stone path edges itself, and a sharp spade-cut edge refreshed each season costs nothing but your time.
Edging is a job most people leave until last and then do on the cheap, and in my opinion that is exactly backwards. The edge is the part of a garden you see from every angle, it is the part your mower fights with every month, and it’s what determines whether your gravel stays on the path or ends up everywhere.
I have spent 15 years installing and, more often than I would like, re-installing garden edging across Britain, and almost every failure I get called out to comes down to one of two mistakes: the wrong type of edge for the job, or the right edge buried nowhere near deep enough. This guide covers both. Each section gives you enough to decide what your garden actually needs, with the deeper build guides linked as they come available.
Do You Actually Need Garden Edging?
Strictly speaking – not always – although I love it. A properly excavated and dry-laid stone path holds itself together and needs no edging material at all; some well-made paths and patios genuinely edge themselves.
Edging Is it important whenever two surfaces meet and one of them wants to move. Soil stays in the bed instead of washing onto the lawn. Grass is far less likely to creep into the planting area. Loose gravel stays on the path instead of migrating into the border. Paved areas stay locked together instead of slowly spreading at the margins.
My rule of thumb: if the surface is loose (gravel, bark, soil raised above lawn level), it needs a physical edge. If it is bound or self-supporting (a mortared patio, a well-built self-binding gravel path, a lawn meeting a lawn-height bed), you have a genuine choice, and a spade-cut edge or a band of dense planting can do the same visual job for a fraction of the cost. Edging is a tool, not a rule.
What’s the Difference Between a Kerb, an Edging and a Mowing Strip?
TLDR: kerb if vehicles are involved or you want to raise soil level behind it, edging for beds and paths, mowing strip if you have a kerb or wall meeting a lawn and you don’t want to strimmer along it every fortnight.
Most people use these three terms interchangeably. They’re not the same thing, and using the wrong one for the job is one of the more expensive mistakes I see on other installs.
A kerb has a raised face, called an upstand (or check-upstand in trade language), that sits above the surrounding surface and physically stops vehicles, cyclists, or feet from crossing the edge. You need a kerb anywhere a driveway, parking area, or hard-trafficked path meets a lawn or planted area. A kerb also needs to be set in concrete haunching (a bed of concrete behind and below it) to hold that lateral pressure, a sand-set kerb against a wheel load will fail. Kerbs are also useful for raised planting beds, because the upstand lets you build the soil level up behind it, which gives plants more root depth and better drainage.
An edging sits flush or very slightly proud of the surrounding surface. It restrains paving and defines a line, but it has no check function. It’s what you need for garden beds, borders, and paths where nothing with wheels is going to push against it. The installation requirements are lighter, the cost is lower, and in most garden settings it’s the right call. The problem comes when people install edging where they needed a kerb, and then wonder why the gravel or soil keeps creeping out under wheel pressure.
A mowing strip is a specific solution to a specific problem. If you have a kerb or a wall sitting directly against a lawn, the kerb makes it impossible to get a mower tight to the face. You end up having to go back with a strimmer every time you cut the grass. A mowing strip is a narrow band of flush paving laid right against that kerb or wall, typically 20 to 30cm wide, which moves the edge of the lawn away from the vertical face so your mower can pass straight over it. It gives you the vehicle-containment function of the kerb on the paved side and the mow-over simplicity of a flush edging on the lawn side. It’s a bit more work upfront, but the ongoing maintenance saving is real.
Choosing an Edging Material
Once I know the type of edge the job needs, the material choice gets much simpler. For most cases, my shortlist is steel, stone, and brick, with timber for the right rustic setting. Here is how the main options actually compare:
| Material | Realistic lifespan | Best for | Watch out for |
|---|---|---|---|
| Steel strip (galvanised or Corten) | 15+ years | Crisp lines, curves, modern gardens, grass barriers | Buy flat strip, not corrugated. Corrugated galvanised steel catches debris and looks worse for it; it is the budget cheat I would skip. |
| Stone (setts, cobbles, cut stone, ashlar) | Decades; can be lifted and reset | Bed edges, path edges, raised beds; the site’s home territory | Stick to one type of rock per garden. A hodgepodge of different stones reads as clutter, not character. |
| Brick (soldier course) | Decades if set right | Paths, patios, traditional gardens | Set in mortar if the adjoining paving is mortared or you get cold winters; sand-set bricks work loose otherwise. |
| Concrete (poured, or edging units on haunching) | Decades | Restraint edging that has to hold paving in place | Effectively permanent. You will not be lifting and reusing it. |
| Timber | 3 to 10 years depending on species | Rustic and informal gardens, raised beds (sleepers) | Pressure-treated softwood cracks and deteriorates. Hardwood sleepers last; cheap softwood boards in soil contact do not. |
| Plastic strip | 2 to 3 seasons | A stop-gap while you save for something better | UV makes it brittle and root pressure works it out of the ground. I have yet to see a plastic strip edge that was still doing its job after a few summers. |
Two design details that save people from ugly results:
- match the unit length to the line type: short units (setts, cobbles) lay smooth curves, long units (cut stone, steel lengths) suit straight formal runs. Buy small cobbles for a wavy bed and long stones for a formal edge, not the other way round.
- height changes function: flush with the ground gives you a mowing strip, slightly raised defines the edge, and stacked flat stone up to about 45cm high gives you a raised planting area that also stops soil washing down a gentle slope.
A full comparison of every material, including the spin-off cases like Corten steel and reclaimed stone, deserves its own page and will get one. For now, the table above is the decision most gardens need.
Installation Basics: Depth, Base and Sequence
The install is where cheap edging and expensive edging end up performing the same, because depth and base matter more than the material. Bury a third to a half of the edging’s height, sit it on a compacted crushed gravel base, and install it before the surface material goes down, not after. Skip any of that and the ground movement will find your edging inside two winters.
I have written the full step-by-step separately, including exact trench depths per material, the sequence rule in detail, and the corner-folding trick for metal edging that the kits never explain: how to edge a garden, the complete install guide.
Why Garden Edging Shifts, Lifts or Fails
Failed edging nearly always fails in one of four ways, and each points to a different cause:
- The whole line lifting together over winter is frost heave: water in a poorly drained base freezes, expands, and pushes the run upward;
- One loose end pulling free is stake failure, usually stakes that were too short or too far apart;
- A sag in the middle of the run is base failure; or,
- Plastic that has gone brittle and popped out is simply plastic doing what plastic does after a few years of UV and root pressure.
To returning clients who wish to improve their skills, I advise them to: diagnose before you dig. If the failure is one bad spot, reset that section with a deeper trench, a compacted gravel base, and/or longer, heavier stakes at closer spacing. If the whole run fails every year, the material has hit its limit and the fix is a swap, usually to steel or set stone, not another reset of the same strip.
And I will give you the honest answer most online sellers articles will not: in frost-prone parts of the UK, even a properly installed rigid edge can need resetting after a cold winter. Anchoring helps but is only moderately effective against ground that physically moves. Flexible steel tolerates that movement far better than rigid materials, which either lift or snap. You cannot fully engineer around frost heave; you can only choose materials that adapt best to the conditions.
How to Stop Grass Creeping into Beds
The way to stop grass creeping into beds is simple; the barrier provided by the edging has to go deeper than the roots travel, and that number is 10cm or greater. Creeping grasses spread by rhizomes (horizontal underground stems) that run just below the soil surface, and they cross under any edging shallower than that. Couch grass (Elymus repens) is the notorious offender, with creeping bents and creeping fescue close behind. Metal or stone edging buried 10cm minimum, 15cm for comfort, stops them cold.
Obviously, the no-material alternative genuinely works too: a sharp, vertical spade cut 15 to 20cm deep along the bed edge exposes the rhizomes to air and stops them travelling – it just requires regular maintenance. However, it only needs refreshing once or twice a year to stay effective. Mulch on its own won’t do it. A 10cm mulch layer kills the grass leaves it covers, but the rhizomes keep pushing underneath, and cardboard breaks down before the grass gives up. Mulch buys you a season; a buried barrier is indefinite.
Lawn Edging, Gravel Bands and Mowing Strips
The lawn edge has one non-negotiable number: anything the mower needs to pass over must sit no more than 2.5cm above ground level. Go higher and every cut ends with you going back around the edge with a strimmer, which is exactly the chore a mowing strip exists to remove.
Gravel lawn edging is the save when you have already got stone sitting proud of the lawn and lifting it is not an option. Lay a band of gravel, mulch or embedded stone between the lawn and the raised edge, and that band takes over as the mow line with the mower wheels running along it. Barely anyone writes about this trick and it has rescued plenty of over-tall edges. A 10mm gravel from the Outdoor Aggregates range is the size I reach for, because it beds down flat enough for a mower to ride over without spitting stone.
For the no-material lawn edge, a half-moon edger cutting a sharp vertical line does the same job, refreshed once or twice a year. I cover the exact depth and technique in my installation guide.
Edging and Borders for a Gravel Path or Patio
No matter how much I love gravel in many different types of settings, loose gravel migrates. Without a contained edge it works its way into the adjoining lawn, beds, or roadside. From there, you would generally need to rake it back every now and again, but most people give up before the race begins. This is the one place I treat edging as close to mandatory, with a single exception: a well-built dry-laid stone path can hold its own line.
The two edges I rate highest for gravel are a brick soldier course (bricks stood on end in a trench, edges butting) and flat steel strip sunk so only the top edge shows, which is the choice when you want the path to read as edgeless. Set the edge flush on the lawn side so the mower passes over it, and slightly proud on the bed side so the gravel stays put. Oh, and treated timber can also look great in a rustic setting.
For a driveway or anywhere cars will push against the edge, go back to the kerb section above; a flush garden edging strip against wheel load is a goner. Whatever edge you choose, the gravel itself lives or dies on its sub-base, and I’ve set out the full build, depths and order in how to lay a gravel path. A patio install follows the same layers as the path, and I have set that build out, depths and falls included, in how to lay a gravel patio. If you have not settled on a surface yet, start with choosing a patio surface.
Edging for Steps, Slopes and Raised Beds
Steps need edging for a functional reason, not only a decorative one: stones set on edge along the outside of a step run hold back the soil that would otherwise wash down and turn the steps muddy. The good thing is that with an edge, the stones do not need to be flat and geometric either. Rounded stones work well, provided each one is firmly seated, and look better in informal gardens.
For raised beds, this is where the kerb earns its place in a garden. The upstand lets you elevate the soil level behind it, which increases root depth and improves drainage, and both of those benefit the plants directly. Stacked flat stone works up to about 45cm high as a raised planting area. Anything above that you are in retaining wall territory, which is a different build discipline with proper structural rules – I don’t dry-stack my way past that line. On the formal end of the scale: heavy granite blocks only need setting about 5cm deep, because their weight does the anchoring that a deep trench does for lighter materials.
Cheap, Reclaimed and No-Material Edging Options
The cheapest genuinely good edging is reclaimed. Bricks from demolition sites, skips and reclaim yards make a proper soldier-course edge for a song. Reclaimed stone, old kerb stones and garden-clearance fieldstone turn up constantly on Freecycle, Freegle and local community groups. Stone also persists without costing you, ever again: when it does eventually shift, you lift it, fix the base and set the same stones again. Warped, cracked plastic and concrete-set edging do not give you that second life.
Logs and fallen limbs give a rustic edge for nearly nothing, with an honest lifespan of 3 to 5 years before rot claims untreated wood in soil contact. And the spade-cut edge remains the only truly free option: no material at all, just labour and a half-moon edger (ideally).
Cheap edging is only cheap once, so where your budget allows, do the ten-year maths before buying the cheapest strip on the shelf, though. A £30 plastic strip replaced every 3 years costs more over a decade than a £150 steel strip that lasts 15.
Living Plant Edging as an Alternative
A dense band of low planting can be the edge itself, and in an informal or cottage garden it is often the best-looking option. My working shortlist for our conditions: lavender, catmint (Nepeta) and hardy geraniums as low mound-formers, santolina and hebe for evergreen structure, and heuchera, sedum and bergenia where foliage does the work. Dwarf box does the classic formal job but can come with box blight, so consider that as potential future pain. One dominant plant with a second repeated at regular intervals reads as intentional design; a mixed jumble reads as a rustic ‘accident’.
Just recall what a living edge cannot do. It will not retain soil on a slope, it will not stop couch grass rhizomes at depth, and it will never hold a crisp geometric line. The strongest setup I know combines the two: a buried steel edge doing the barrier work underground, with the planting doing the visual work on top. Belt and braces, and neither half is doing a job it is bad at.
Where to Start
Decide the type first (kerb, edging or mowing strip), then the material, then commit to the install numbers, in that order. Get those three decisions right and edging is a fit-once job; get them wrong and it becomes an annual spring apology to your own garden.
If you are ready to build, start with the full installation guide, and if stone or gravel is your material, have a look at our shop to price the job up.
Have you edged a garden of your own? What did you use, and has it held its line over the years? Tell us in the comments.
FAQs
How deep should garden edging be?
Garden edging should be buried a third to a half of its height, 10 to 15cm as a working minimum, on a compacted gravel base. Heavier units need less, because the weight does the anchoring a deep trench does for lighter materials: granite blocks sit happily at about 5cm.
What is the longest lasting garden edging?
The longest lasting garden edging is steel strip or properly set stone and brick, all of which run to decades on a compacted base. Stone has the edge on the other two, because it can be lifted and reset rather than replaced.
What can you use to edge a gravel path?
A gravel path wants either a brick soldier course, bricks stood on end in a trench with their edges butting, or flat steel strip sunk so only the top edge shows, which is what I use when the path should read as edgeless. Timber works in a rustic setting. Set the edge flush on the lawn side so the mower passes straight over it, and slightly proud on the bed side so the gravel stays where you put it. If cars will push against it, that is a kerb rather than an edging, and it needs concrete haunching behind it. Whatever you choose, the path itself lives or dies on its sub-base, and the Outdoor Aggregates gravel calculator will size the stone once you have the edge decided.
Is plastic garden edging any good?
Plastic garden edging is not a permanent edge, because UV makes it brittle and root pressure works it loose within a handful of years. It is fine as a stop-gap if you accept you are buying time, not a solution.
What is the cheapest way to edge a garden?
The cheapest garden edging is no material at all: a spade-cut edge with a half-moon edger costs nothing but labour. Refresh it once or twice a year to keep the line sharp. If you want a material edge, reclaimed brick and stone are often free from skips, reclaim yards and Freecycle.
Do I need to cement garden edging in?
Garden edging only needs cementing in where it has to restrain load: kerbs against vehicles, edging holding mortared paving, brick edges in cold winters. An ordinary bed or border edge holds fine in a trench with tamped soil over a compacted gravel base, and that way it stays reversible.