Landscaper David Dodd offers top tips on all types of edging
Whether it is decorative or functional, edging in landscaping is a vital element to most gardens that doesn’t always get the level of design attention it deserves. Loose materials such as gravel need edging to keep the surface in place, and formally shaped lawns need edging to maintain shape. The three key elements to consider when selecting the right edging are structural integrity, aesthetic value and cost.
What you are edging will determine which material you should use. Lawn to border edging or pedestrian paths only require a light-duty material such as timber. There is plastic lawn edging available from DIY stores, but these are often difficult to install and generally look cheap and nasty. Lightweight metal edging has come a long way and varies dramatically in both thickness and design, which means there’s usually one suitable for most applications, from garden paths to driveways.
For heavier traffic, bricks on edge, pavers and natural stone setts are often more desirable and are usually selected for their aesthetic properties as well as their strength. Edging will only perform well if properly installed with adequate substructure and fixings as required.
Assuming the edging is structurally correct, the next decision is whether or not to make a design feature of it, or allow it to be as low key and unobtrusive as possible. Edging around beds will often become obscured by planting, so as long as it is performing structurally, there seems little point in spending hundreds or even thousands of pounds on a material that will never be seen.
The edging of a terrace or pathway may well be as much of the design integrity as the main body of material. Beautiful edging will enhance beautiful paving, so if it’s going to be on view, let your creative juices flow. Let it contrast and complement, but keep it in scale to whatever it is surrounding.
It is always important to have material budget options to give to the client, and edging is no exception. Timber, while being the cheapest material, does only have a certain shelf life, whereas more rigid materials such as stone or bricks will be more expensive as a capital outlay, but will give you many more years of service if laid properly.
Timber can look wonderful in the right setting. I’m not talking about the ‘log on a roll’ available in most garden centres, but simple timber edging. It’s relatively easy to install and as long as it is pressure treated (tanalised), you should be looking at at least 10-15 years of life. For pathways and borders, 25mm x 100mm is fine, and it’s easy to bend into position for gentle curves. The timber should be pegged every metre with 50mm x 50mm x 600mm pressure-treated pegs. These should be hammered in 25mm below the finished surface so you don’t see them, and then fixed to the board with stainless-steel screws. Always treat any cuts with good-quality clear wood preservative. For straight borders or rural gravel driveways it may be worth considering going up to 50mm thick timber for greater longevity.
Make it metal
Most metal edging is either galvanised mild steel (which can be powder coated) or aluminium. Corten steel has become increasingly popular for those projects that require a greater level of je ne sais quoi and where cost isn’t an issue. If an edge is going to be raised so you see part of the front face as well as the top, it’s worth spending more on bespoke edging, using anything between 5mm to 10mm thick. This will not only be stronger, but also make a real statement.
I’ve always found the more ‘domestic’ system of 1.6mm thick metal with built-in spikes a nightmare to install unless it is in lovely, fluffy soil. If there’s the slightest hint of a stone or tree root, it bends or warps out of shape with the lightest of taps and the finished result can look amateur at best. However, the sturdier L-shaped systems are superb, and are both quick and easy to install. They have a pinning system, but we also lay them on concrete and give a concrete haunch (external shoulder) for added strength.
Metal edging is flexible enough to create both gentle and tight curves and there’s a wide enough range to make it suitable for most applications. While being a very good product, you pay for its performance, but with labour always being the most expensive element of a project, the cost often manages to balance itself out when comparing it with some of the flimsy alternatives.
Bricks & stone
Bricks and pavers are timeless, classic materials and can be laid flat (better using 100mm wide pavers), on edge (65mm brick/50mm paver) or ‘soldier course’ for a wider path or larger paved area. A wider path (1.8m+) can command a 200mm-wide edge, but anything narrower should have the brick or paver laid length ways.
If house bricks are being used, ensure the hollow ‘frog’ is filled with mortar as they are laid, and all brick, paver and stone edging is given a decent haunch (a minimum of 25mm from the top of the unit to prevent a lawn edge from drying out).
Although York and Indian sandstone are very popular, granite is probably the most widely used natural stone for setts, mainly due to it being incredibly hardwearing and coming in neutral colours. Stone setts can be ‘cropped’ or tumbled for a more textured, natural appearance or sawn for a more contemporary look.
These are just a few options – there are many other materials out there – but whatever you choose for your next project, just make sure to check what you want is available in the scale you require, and is suitable for the job.