Lawn and garden edging seems simple on the surface, but small installation errors can completely change the look and performance of your landscape. Clean edges make a garden feel intentional, structured and polished. Messy edges do the opposite.
This guide highlights the most common edging mistakes, why they happen and how to avoid them so your garden looks professionally finished the first time.
What are common mistakes when edging?
The most common edging mistakes include installing edging too shallow, using low quality materials that warp or crack, creating curves that are too tight, skipping base preparation, misaligning panels, forgetting about drainage and soil movement and placing edging where mowers cannot reach.
Many homeowners also underestimate how grass spreads, leading to constant creeping under or over the edging. Avoiding these mistakes is simple with proper trench depth, stable base preparation, quality edging materials, and thoughtful layout planning.
Using materials that don’t last
Cheap plastic edging often becomes brittle, discolours, and warps after a season of UV exposure.
Thin timber rots quickly or attracts termites. Even some metal-look products are simply coated mild steel that corrodes faster than expected.
Reliable options include genuine Corten, stainless steel, recycled plastic, and quality powder-coated steel. Choosing a long-lasting material means you install once and enjoy clean edges for years.
Installing edging too shallow
This is one of the biggest edging mistakes. Edging that sits too close to the surface shifts with weather changes, mower wheels, and soil expansion. As it moves, your clean line becomes uneven.
The simple fix is trenching depth. Most edging performs best with at least one third of its height buried below soil level. This anchors the line, gives the edging structural support, and stops it from creeping upward.
Skipping proper base preparation
Without a compacted base, edging can tilt or sink. Loose soil settles differently along the line, creating waves or bulges. Before installing, scrape out roots, remove soft pockets of soil, and tamp the base so it is consistent from end to end.
The straighter and firmer your base is, the straighter your edging will sit long term.
Overly tight or unnatural curves
Curves look beautiful when subtle but become awkward when forced too tightly. Many materials are not designed for sharp bends and will kink or distort if pushed too far.
Flexible edging like recycled plastic or thinner Corten strips handles curves naturally. With rigid styles, keep curves gentle and pre-plan their shape using a hose or rope to visualise the line.
Misaligned or poorly connected edging pieces
Even a perfect installation can look messy if the joins between sections are visible or uneven. Gaps allow weeds to sneak through and create weak points where soil escapes. Many modern edging systems, like YardSteel Australia, use interlocking tabs or concealed connectors.
Taking a few extra minutes to align joints makes a huge difference in how professional the final line looks.
Ignoring drainage and water flow
Soil expands when wet and contracts when dry. If edging traps water or sits where irrigation constantly soaks the soil, the line can warp or rise. In heavy clay soil this effect is even stronger.
The best solution is to avoid creating a water trap. Ensure edging sits slightly proud of the soil and that the trench drains naturally. Around paths and driveways, consider adding a thin layer of gravel beneath the edging before backfilling.
Not thinking about mower access
A crisp edge becomes annoying if you cannot mow neatly against it. Some installations leave a small lip or raised section that catches mower wheels. Others place edging too close to fences or obstacles.
When planning the line, imagine pushing a mower or whipper snipper along the border. If the path feels awkward, adjust now rather than fixing it later.
Letting grass or weeds creep underneath
Edging is not meant to be a barrier against deep root systems unless installed correctly. Kikuyu, buffalo, and couch grasses are especially aggressive. If the edging is too shallow or gaps exist between panels, roots can creep under and invade garden beds.
Deeper trenching, compacted backfill, and solid joins slow grass movement significantly. In extreme cases, a narrow root barrier installed behind the edging provides additional protection.
Burying edging too deeply
While shallow installation is a mistake, burying edging so deeply that the top is flush with soil is another. When the upper edge disappears, mulch spills over into the lawn, grass creeps inward unnoticed, and the clean visual line is lost.
For most materials, leaving about 10mm to 20mm exposed gives a crisp boundary without being a tripping hazard.
Ignoring soil movement and seasonal changes
Landscapes behave differently through the year. Sandy soil shifts easily, clay expands when wet, and gardens on slopes move slightly downhill over time. These natural changes can push edging out of alignment.
Well-anchored stakes, deeper installation, and compacted backfill reduce seasonal movement. Checking the line once or twice a year helps keep everything looking neat.
Choosing the wrong edging material for the garden style
Sleek gardens with straight lines look best with galvanised steel or aluminium edging. Cottage gardens suit Corten or recycled plastic styles that soften into the landscape. Rustic or native gardens benefit from low, natural-tone materials.
Using the wrong edging style can make the garden feel disjointed. Matching material to garden design creates cohesion without extra effort.
Not planning the layout before digging
Many mistakes begin before installation even starts. Without a clear plan, lines wiggle, curves feel random, and measurements change mid-project. A simple hose, string line, or spray paint can map out the perfect shape.
Taking a few minutes to plan prevents hours of correcting mistakes later.
Overlooking expansion and contraction in metal edging
Metal edging expands slightly in hot weather and contracts in cooler temperatures. If panels are fixed without a small allowance for this movement, joins may separate or buckle.
Leaving a tiny expansion gap between long runs prevents issues later while still appearing seamless once installed.
Backfilling unevenly
If one side is packed tightly while the other is loose, edging will tilt. Backfilling should be even on both sides and lightly compacted as you go. This supports the profile and prevents gaps or shifting over time.
Not checking level as you go
The eye can be deceiving when working along curves or slopes. A spirit level or line level helps ensure the top of the edging is consistent. Even a slight rise or dip becomes obvious once the garden is finished.
Checking level frequently saves time and delivers a more professional look.
Failing to clean up after installation
Soil left on top of metal edging encourages surface staining, particularly with Corten during its early weathering phase. Clearing soil, rinsing off debris, and sweeping the area helps the edging settle in cleanly and makes the finish look sharp from day one.
What these common mistakes mean for your garden
Most edging issues come from rushing or using the wrong materials. The good news is that nearly all problems are preventable with a little planning. When installed properly, edging defines your garden, keeps mulch in place, prevents grass invasion, and creates that clean, professional look that elevates the entire landscape.
How to avoid edging mistakes altogether
Choose quality materials suited to your garden style, plan your line before digging, dig deep enough for stability, prepare your base, align your joins, allow for drainage, use enough stakes, and keep a small portion of the edge showing above the soil.
These small steps make edging easier, longer lasting, and visually impressive.
Final thoughts
Edging mistakes can undermine an otherwise beautiful garden, but they are simple to avoid with the right approach. With proper installation, thoughtful planning, and durable materials, your edges will stay straight, clean, and low maintenance for years.
A well-edged garden not only looks better but is easier to care for, more organised, and far more enjoyable to spend time in.