It can be a tricky thing indeed to get the best possible use out of a sloping garden. While most plants will not mind a slight incline, working or playing on a slope can be highly dangerous, especially during wet winters. A sloping garden can also prevent you from installing some of the most valuable garden features, such as patios or wooden decking.
Even for seemingly unusable green slopes, there is a solution: tiered gardening.! This involves digging into the sloping earth to create steps and ledges, leaving you with valuable flat space to use however you wish. The work required involves a great deal of landscaping and careful planning, but at the end you will be left with far more space for relaxing, gardening and entertaining guests.
If you want your tiered garden project to be successful, you cannot afford to ignore the garden design phase. Remember, a well-designed garden is not just about choosing features; it is about marrying these features in a single comprehensive picture.
This is particularly important with tiered gardens due to the structural calculations involved. Each ledge will require a retaining wall strong enough to hold back the earth behind it, and you will also need to ensure sufficient drainage and safely positioned steps.
For help in designing your tiered garden, your best bet will be to speak to a local landscape designer. The garden clearance phase may last several days, and you may need to hire a skip to help remove any unearthed stones or leftover soil. It can also be a good idea to ask a local gardener for advice on choosing plants for your garden’s different tiers, which will each offer their own growing conditions.
As you might expect, the first and most important stage of designing a tiered garden is to decide exactly how the tiers will be formed. This is about more than simply digging chunks of earth from your slope: each tier will require a retaining wall to hold back the earth behind it. To give you a clue, a cubic foot of wet soil weighs around 45kg - if your ledges are unsupported, all it will take is one particularly rainy day to bring all of your tiers tumbling down!
Exactly how your tiers will be designed will depend on the size of your garden and the steepness of your slope. Particularly steep gardens may require ‘terracing’, which involves creating several short levels, though generally speaking your retaining walls should not be any taller than 2m.
A local landscape designer can help you to get a solid plan in place before the work starts. Remember, there will be a great deal of physical labour involved in digging out your tiers, so the key will be to work smart: consider which features and furniture you would like to include, calculate how much space they will require and ensure that you can create tiers which are large enough. If you don’t have the space, ask your landscaper about alternatives! At the same time, try to show a little creativity: a staggered tiered garden with ledges of different shapes and sizes can look quite attractive.
During the garden design phase, consider whether your slope rises towards your property or away from it. Either answer offers unique challenges and considerations; for example, if your home is at the bottom of the slope then top of your garden will enjoy a great deal of warm summer sun, as well as chilly winter winds. If your slope is facing away, safety features like fencing and handrails will be far more important. On the plus side, your retaining walls will not be visible from your property, so you will not need to worry as much about making them a decorative feature.
To ensure the long-term health of your tiered garden, it will be important to take proper drainage into account. You do not want the bottom of your garden to be flooded - not only can this leave you stranded in your home, it can also cause erosion. To provide safe drainage, leave enough soil exposed to be able to soak up rain water. Alternatively, you can ensure that cemented stone, concrete or other impermeable materials are installed with ‘weeping holes’ to allow water to drain through.
Another key aspect of your tiered garden will be safety, especially if you have young, elderly or disabled family members living with you. Your steps cannot be too steep and they should also be flanked by at least one solid handrail. Lighting will be crucial for guiding people around your garden, though it can also be a valuable decorative feature. An enduringly popular choice is to install LED lights along the ledges and steps of the garden, showing off its best features while also ensuring that the routes are well marked.