Garden edging
Whichever type you choose, edging provides the essential finishing touch to your landscaping, writes DERYN THORPE
Edging is the unsung hero of the garden, creating defined lines that give the landscape a clean, finished appearance. Often a feature in its own right, an edge provides a practical garden barrier, stopping lawn from growing into flower beds, marking a division between the different planting areas in the garden, and holding back the soil and mulch in raised beds.
Edges can be as simple as a spaded trench between the lawn and garden bed, but most gardeners opt for a long-term approach, using a physical barrier made from timber, metal, plastic, rubber, stone or brick. Choose the one that suits your garden style and budget.
Consider practicality before deciding on an edge. If it abuts a lawn, laying it about 1cm proud of the soil enables the mower to cut the grass cleanly to the edge, with minimal need for further edge trimming. This works best with the less-invasive lawns, such as buffalo.
If the edge is raised above the lawn, you’re going to need to trim it with a line trimmer or hand shears. Raised edging is best for beds such as vegetable plots, where it provides improved drainage and prevents material from spilling out onto pathways, as ongoing soil improvement with organic matter increases soil levels.
You can use edges in creative ways, as dividers between gravel mulch and plants, or to lock in paving or compacted or loose-fill paths. Linear edges are usually marked out using a tightly stretched string line, and a garden hose is a simple way of marking out a curved garden bed.
EDGING TYPES
The type of edging material you decide to use depends on two main factors: your garden style and your budget. PLASTIC
This is sold as rolls of flexible, UV-resistant material that you cut to the desired length and secure in the ground with spikes. It’s an affordable option in green, brown or black, in widths ranging from 7.5cm to 15cm. Ends should be overlapped if more than one roll is used.
Plastic edging also comes in styles that resemble short timber palings. These sit above soil level, secured with spikes.
RUBBER
Recycled rubber edging is flexible, and formed to resemble etched stone or brick. It is lightweight, easily installed and sits above the ground, secured by nylon spikes.
TIMBER
Timber provides a traditional ambience and is best for straight edges, unless you use the flexible, roll-out edging, available in bamboo or pine, which sits above the ground, secured with timber pegs.
Durable composite timber, which is a blend of wood and recycled plastic, is also flexible and available in rolls or cut lengths.
Treated pine edging is preserved with chemicals that can leach into the soil, so if you are using it in areas where you are growing edible plants, it’s best to line the beds with plastic. Many people prefer to use untreated timber when building vegie beds, to avoid contact with chemicals.
Rustic timber sleepers have long been a favoured product for raised garden beds because they are durable, easy to install and long lasting. Most railway sleepers are treated with chemical timber preservatives, so bear this in mind if you are planning to use them for your vegie gardens.
To prevent grass invading garden beds, bury half the width of timber edging into a trench and then support the structure with timber or metal pegs. These can be attached to the edging with timber screws.
STONE
Stone creates a feeling of tradition and permanence. A single edging of free-form rocks can be difficult to maintain, as the plants and lawn can grow through gaps.
A better option is to use flat rocks or stone, such as granite or limestone that has been cut into uniform blocks or tiles. The stone is usually cemented into place and the gaps filled with mortar.
Stone edging also creates a statement when built into a low wall using blocks, free-form rocks or gabion baskets.
BRICK
Bricks and masonry blocks make a handsome edge and are appreciated by gardeners who like a wider border that keeps grass from the garden, while allowing any free-flowing perennials to informally spill over and soften the edge.
You can use recycled bricks, but often pavers are less expensive and easier to install. These can be laid flat, either end to end or side by side, and cemented into place, or butted close together, or laid with 10mm gaps filled with mortar. METAL
Metal edging is a premium product that is durable, sleek and more expensive than other edging options. It is one of the top choices for landscapers, as it is flexible enough to be used for circular edging, is reasonably quick to install and provides a smart, hard-wearing, contemporary finish.
There are different options for metal edging, including weathering steel, which has an attractive, contemporary, rust finish; galvanised steel, which is coated in zinc to prevent rusting; and lightweight aluminium. Available in curved or linear forms, these are all resistant to physical damage by trimmers or lawn mowers.
Steel edging needs to be secured by connectors, pins and spikes. Some brands manufacture both low edging and tall edging, which is suitable for raised-bed planter boxes.
Another option is galvanised-steel corrugated garden edging, which is laid end to end in shallow trenches, overlapping each of the sections.
Decorative wire edging, coated in a protective layer of PVC plastic, is easily installed and comes in designs that add period-style ornamentation to beds. Its wire ‘legs’ are simply pushed into the ground, so it requires no digging.
CONCRETE
Continuous concrete edging is laid by contractors and is available in a wide range of colours and profiles. Laid in a continuous stream without gaps or joins, the formwork and moulds can create straight, curved and decorative patterns.
Pre-cast concrete edge blocks come in either 1m or 2m lengths, with curved and angled pieces also available. These products usually sit above the level of the garden bed, so it can retain mulch.
RECYCLED MATERIALS
Use your imagination and create edges with materials such as roof and floor tiles. Or, for a quirky feature, try coloured glass bottles or old plates, although these are more decorative than practical.