Landscaping must be designed with respect to existing architectural styles and individual tastes, but also according to the constraints of the location or type of housing. The most common constraint is the relief which can be expressed by slopes at the level of the natural ground or caused by the type of housing (house on basement). There are several solutions to develop this type of space in order to transform this constraint into a major asset.
The spontaneous choice: underpinning
When a lot has a steep slope and little space, the most common method is the retaining wall. This can be made of concrete or stone, but it can also be made of elements such as wooden sections (sleepers, logs) or stone slabs (slate or sandstone slabs) set in concrete.
For this type of installation, three things are essential. First, the elements must have a sufficiently large cross-section to resist the thrust. In addition, it is important to give what is called a "fruit" to the structure (false plumb pushing upwards) in order to reduce the thrust.
Finally, they must be embedded in the ground to a depth of at least one third of the apparent height. This choice is undoubtedly one of the most expensive solutions to its installation but has the main advantage of not being greedy for space.
A more flexible and equally reliable solution: the rock garden
The rock garden is a solution that allows you to combine mineral and plant materials by playing with volume and mass. The mineral can be selected according to its size, shape, color and structure.
Volcanic rocks such as pierced stone and pozzolan are widespread but are more often used when the planted areas are larger and the slopes are smaller. Their density is lower, which reduces their capacity to retain the thrusts associated with steep slopes.
For Japanese or heathland gardens, large granite pebbles provide an interesting contrast with pine bark and heathland plants.
Finally, you can use rocks from your region when there is a lot of slope (sandstone blocks, shale, etc). With their high density, they can be placed almost vertically without the risk of falling. Moreover, being extracted in your region, their cost is much lower and is favourable to more limited budgets.
For the creation of a rock garden two rules are essential. It is necessary to bury the boulders sufficiently by about a third of their height, and it is necessary to start by putting the largest blocks at the base of the set and finish with the smallest.
Association of iron and stone: gabions
This association is very old and uses the method of the XVIth century which consisted in filling wicker baskets with earth and stones, to protect oneself from bullets and splinters. Now these structures can be a very good solution to retain the earth while offering a structured and modern architecture. The filling of gabions can be done with all types of stones, allowing to play with colors and shapes. Example: white pebbles with slate waves. These galvanized steel blocks are cubic and extremely resistant once filled.
Originality and reliability
A sloping ground should be seen as a quality and not as a constraint. There are many ways to enhance it and make it a pleasant space to look at and move around in. You just have to use your imagination, which, combined with the strength of the materials that nature offers, can only give a unique and reliable result.
