Keeping grass and other plants in check may be a major function for garden edging but it can also be used to control erosion and water flow, keep mulch in place and facilitate easier mowing. It can also help to define the character of your garden, whether you desire a neat controlled look or a quirky and more personalised look.

The simplest and most natural way to define a garden is to use a ‘spade edge’ or living edge. Essentially, a V shape trench is cut around the garden bed. Regular visits with the spade during the growing season keep the grass at bay. The garden bed can then be edged with plants to define it and hold the mulch back.

Timber is another fairly low cost option with minimum preparation required. Smaller sized timber provides adequate edging between garden beds and paths and is quite flexible allowing you to form graceful curves. However, if used on the edge of a couch or kikuyu grass lawn, this size will not provide enough of a barrier. Larger timbers, capable of providing a barrier more than 120mm into the ground will work better at the expense of lower flexibility. For durability, use hardwood.

Rocks are a great option for a less formal look. By using naturally formed boulders or the sharper faced quarried rock, you can create a multitude of styles. Placing the rocks without much thought will give a very loose, rustic feeling. Occasional larger rocks will give the plants something to peek out from behind. Taking the time to fit the rocks together can give you a flat face and a level capping with a minimum of gaps. This provides an altogether more formal and considered look. The rocks can also be set in concrete to provide a better root barrier and be finished with a mowing strip for easier maintenance.

Another option with flexibility in style is the house brick. New bricks set on concrete will give a rigid well defined edge. By matching the bricks used to build the house, the garden becomes more contemporary and has a ‘new’ look about it. Used or mismatched bricks set upright or at a 45 degree angle instantly gives the garden a 19 century cottage look.

One of the most commonly used ways to define a garden bed, especially in new estates is the continuous cast concrete edging. It is a fairly fast process with flexibility to allow for good curves. Once in place, soil and turf can be laid up to it on one side with plants and mulch filling in the other. Many profiles are available and the concrete can also be left plain grey or have colour added to it before it is poured.

There are many other cast concrete, plastic and aluminium products for edging, which are available through your local landscape yard, nursery or hardware store.

For those who want their garden to have a unique flavour and harbour artistic tenancies, a combination of materials can be used. Traditional edging mixed with found objects and logs can create endless fascination for a visitor. Shells set in concrete, old machinery parts, broken ceramics or mosaics popping up between plants are a favourite with children. They will explore the garden to discover what else has been used. These gardens often take years to develop and are in a constant state of flux as new components are found and given a home.

However you choose to draw that line in the dirt, as a gardener you will feel more satisfied by casting a bit of order into the wild world of plants.