Simply heaping up gravel and rocks and planting mountain plants in between does not make a rock garden. Some preparation is required to ensure that the mini mountain world actually survives more than just one season, blossoms and thrives. In particular, the substrate of the rock garden must be carefully designed and layered.
The better the subsoil is prepared, the less gardening there will be later
Prepare the rock garden substrate - Here's how
Above all, the subsoil decides on the success or failure of the rock garden. So that no waterlogging forms, the plants get the right soil for their needs and the right living environment is created at all, it is best to go deep first.
Combat root weeds and eliminate unpleasant surprises
Before you can really get started, you first have to clear the area intended for the rock garden from weeds. In particular, root weeds such as thistles, bindweed, couch grass, sorrel, horsetail and groundweed should be permanently removed - this only works by weeding and digging up. Other unpleasant surprises such as buried building rubble or even rubbish should also be removed completely.
Excavate the floor and replace if necessary
In general, it makes sense to excavate heavy and compacted soil in particular, i. H. it must be removed. How much soil you want to remove depends on the actual soil conditions - around 40 centimeters is ideal. If the mini-mountain is to be built on a predetermined slope, dig a trench about 30 centimeters deep at the foot of the slope, the side wall of which runs in line with the slope and perpendicular to the slope on the opposite side.
create drainage
A weed fleece (€21.70) is placed on this excavated subsoil, on which you lay a layer of gravel or grit about five centimeters thick. This forms the base for the drainage pipe, which is intended to prevent waterlogging. So-called drain-flex pipes with a diameter of 65 to 80 centimeters are well suited for this purpose. At the deepest point, the pipe must have an outflow that either simply runs outside, into a sewer connection or into a seepage shaft. Another layer of gravel or grit, about five centimeters thick, is placed on top of the pipe and finally the earth.
tips
If you want to lay paths in the rock garden, they also need a substructure. This prevents the path plates from sinking in and ensures that they stay in place.