table of contents
- The raised bed filling
- Location 1
- Location 2
- Location 3
- Location 4
- Location 5
- Location 6
- When to invest
- frequently asked Questions
A raised bed saves space, is easy to maintain and promises high yields. For it to work, however, it depends on the correct raised bed filling.
In a nutshell
- Raised beds are built in several layers from bottom to top
- Towards the top, each layer is made from finer, more rotted material
- If a layer is made too thick, the function of the layers below will be restricted
- The lower layers in particular must be carefully created as they cannot be reached later
- Depending on the materials used, raised beds have a different lifespan from one to several years
The raised bed filling
The grown soil has a very heterogeneous structure in several layers. It thus fulfills a wide variety of functions that are essential for the growth of plants. Instead, raised beds only have the layers that you plan for when you create them. So that a raised bed also works ideally as a planting base, you should heed the following procedure layer by layer when setting up the raised bed filling.
Note: The layers described are built up one after the other from bottom to top. This means that layer 1 is also the first step towards the finished raised bed filling.
Location 1
- What: protective grille
- With what: vole mesh, rabbit wire, other permeable metal meshes with a mesh size of 1 to 2 centimeters
- How: lay flat on the floor and attach to side walls all around (e.g. B. Staples or staples)
- How much: single layer
- Why: against invading animals such as mice, rats, dormice etc.
Location 2
- What: rough pruning
- Material: various materials such as branches, waste from hedge cutting, etc. in different lengths around 30 to 50 centimeters
- How: Place the pruning in alternating directions, avoiding large holes or imperfections
- How much: 20 to 30 centimeters
- Why: as a drainage layer against waterlogging and rot, as well as for better ventilation in the raised bed
Location 3
- What: fine pruning
- With what: finely chopped branches, shredded perennials, chopped material
- How: apply over a large area as a loose fill on a coarse cut, using finer material from bottom to top
- How much: 15 to 20 centimeters
- Why: as a flat surface on the coarse cut of wood, against the fine components of the following level above
Tip: Instead of fine pruning, long-stemmed grass cuttings are also suitable. However, this rots faster and develops a significantly more inhibiting effect on ventilation. However, grass clippings are convincing due to the high proportion of nitrogen, which sooner or later benefits the planting.
Location 4
- What: coarse organic decomposition material
- With what: manure, coarse compost
- How: apply loosely as a closed layer
- How much: 20 to 30 centimeters high
- Why: as a nutrient base, especially nitrogen
Tip: In addition to the nutrients, the layer of manure or compost also generates heat due to the progressive decomposition. This warmth is a kind of natural frost guard for sensitive plant roots, especially in the transitional periods. However, this heating can hardly be regulated or "refilled".
Location 5
- What: fine decomposition material
- With what: fine, heavily rotted compost, grass clippings, animal litter
- How: as a surface applied substructure of the later planting layer, ideally several different fabrics in layers
- How much: around 10 centimeters
- Why: as a supplier of various nutrients such as nitrogen, potassium and phosphorus
Location 6
- What: planting layer
- With what: garden soil or plant substrate, e.g. B. Mixture of soil and humus
- How: as a top layer on previous layers full and over the entire surface
- How much: at least 10 to 15 centimeters
- Why: as the actual growth layer for all planned plants
Attention: It is true that one reads again and again “up to the top” for the final substrate layer regarding the layer thickness. However, if the substrate layer is too thick, the underlying layers of the raised bed filling can no longer contribute effectively to the functioning. Instead, choose the bottom ventilation layer so thick that the following layers can be dimensioned as specified.
Here you can download the PDF for the ideal raised bed filling. This means that you always have a helpful guide at hand when creating your raised bed.
When to invest
If you have carefully followed the structure of the layers in the raised bed, the question now arises as to whether all of the loose components do not sink in over time. Indeed it is. Especially the very loose, coarse layers will initially settle after watering or intensive irrigation and decrease in thickness. Depending on the plant, this can lead to a considerable problem if the fine plexuses of roots in the moving soil are damaged. So that the plants used do not suffer from these changes, you should proceed in such a way that you ideally create the raised bed in autumn or winter. Then the materials can settle and the bed is available for you to plant safely in spring.
frequently asked Questions
If you fill your bed completely with potting soil, it will rot quickly due to a lack of ventilation. And the water balance can also be disturbed, so that you have to expect waterlogging in particular.
Yes that's right. A raised bed has only a limited shelf life, as the materials used continue to rot and, with increasing decomposition, condense into a compact mass.
In principle, there are several ways to reach the goal, regardless of the position of the bed structure. If you are missing large branches and twigs, you can create an alternative drainage and ventilation layer using straw or even pebbles, for example.
Refilling is possible to a certain extent. It is important that the lower layers for ventilation and drainage are still in tact. Usually fresh manure or compost is added to the penultimate level. For this, at the end of the planting period, half of the top layer is pushed aside, the manure is installed and then the second side is filled in the same way.
It is not possible to provide precise information on the usability of a raised bed. Depending on the materials used and the size of the raised bed, the construction can usually be used for several years without any problems.
