Designing a garden's grade

Garden development often requires some site adjustment that involves shaping the terrain to resolve drainage problems, enhance function and improve aesthetics. This is called grading. 

A well thought out grading design increases the usefulness of a site. For instance, flattening a section of a slope can create a surface for a recreational playfield, a swimming pool or parking for cars.

But grading also unlocks the opportunity to create garden “rooms” at different levels of a site. Adjacent garden rooms may be separated physically and visually simply by a change in level rather than using walls and planting. Here are some more tips on how to design your grade.

Plan

Grading can be as simple as installing a curb to hold the soil back from a driveway or may involve deploying earthmovers to chop off a hillside.

Whichever situation you are confronted with, a grading exercise should not be left to chance. It should be well planned in order to take full advantage of the opportunities presented by your site’s natural terrain, mitigate potential problems and reduce costs.

Grading typically involves cutting or excavating the soil in some places to lower the existing level and filling other areas to raise the level.

In order to reduce costs, a good grading plan should ideally balance the volume of excavated soil with the volume of soil required to level up the other areas within the garden.

Additionally, retaining walls of stone, brick, concrete or wood ties may be necessary to support the restructured levels and prevent erosion.

These, too, need to be planned so that they are not only functional but also go towards enhancing the overall garden and architectural design.

Create spaces

Grading provides an opportunity to create beautiful spaces full of movement and drama between the different levels of a site.

Working your plan around the site’s natural terrain will create a more natural effect, while working with terraces and retaining structures create a more formal and contemporary design.

Your main objective will be to create spaces at different elevations for visual interest and depth and linking these in an attractive and functional manner.

Avoid drastic changes that will require huge and imposing retaining structures. For practical purposes, spaces with only a slight incline can be treated as flat.

However, if completely level areas are needed, for example, to accommodate tables and chairs, this should be considered carefully so that drainage is not compromised.

Drainage

The need to properly drain your property cannot be overemphasised. Stagnant water or water that drains towards the house can cause a myriad of structural and health problems, not to mention destroying your plants and garden.

The easiest way to deal with drainage problems is to slope all land, patios, walkways and driveways away from the house.

Once you get that right, the only other thing you need to do is to direct the water through surface or underground channels to storage facilities or places where it will easily percolate or flow into a municipal or other common drainage facilities.

Photo: www.hickoryhollowlandscapers.com

The writer is a landscape architect