Level plant terraces have been known for many thousands of years from the most diverse cultures and continents: Just think of the Hanging Gardens of Babylon to the rice terraces in Asia. Raised beds with stairs are an effective measure to prevent soil erosion on steep slopes, to use rainwater run-off sensibly and to create level planting areas.
Slopes can be designed decoratively with raised beds in a staircase look
What are stair raised beds?
Stair raised beds are beds that are staggered one behind the other like steps. They can be cared for standing or sitting. The planting steps offer a whole range of advantages: the brick support structures secure the slope, the level beds increase the planting area and - last but not least - the beds can be cared for safely, ergonomically and easily.
To be on the safe side, ask a structural engineer
The design of such a stair raised bed is not easy, especially if it is a very steep garden with difficult geological conditions. Even the planning of the stairs, the measuring and the subsequent descent poses problems for the layman. Retaining walls, for example, have to be calculated and built in such a way that they absorb the pressure on the slope. You can confidently climb smaller embankments yourself, but you should always ask a civil engineer or structural engineer for higher slopes with walls stacked on top of one another and unclear ground conditions.
Which materials are best?
Natural stone or concrete blocks, which can be selected according to size, weight, interlocking and other characteristics, are well suited for the construction of such stair-raised beds. When building, you should also distinguish between walls with laid stones and palisade walls. While compacted gravel foundations about 40 centimeters deep are sufficient for the former, you need a deep trench for palisades. This must accommodate the stone pillars up to a third of their length.
Planning stair raised beds
So that you can easily care for the plants in the stepped raised beds, you should calculate the dimensions of the stairs and walls as follows:
- The bed height should be either about 50 centimeters (care while sitting) or 80 to 90 centimeters (care while standing).
- The planted bed depth should not be more than 70 centimeters together with the wall (pay attention to the thickness!).
- With two or more beds staggered on top of each other, a path width of at least 40 centimeters must be added. Otherwise, the next higher bed can be cultivated.
- It is best to divide bed depths of 160 to 200 centimeters into two planting strips with a middle path and a path in front of the next higher planting terrace.
tips
On steep slopes, you also have to plan the necessary stairs very carefully: for a bed height of 90 centimetres, six steps of 15 centimeters each are required.