Creating a natural stone wall

Natural stone walls are components of all ancient cultural landscapes. They were piled up 'dry', i.e. without mortar, and have fulfilled a wide variety of functions throughout history. They can simply be a demarcation to the neighboring property, so create protective and quiet zones, so for example also in cemeteries.

In the agricultural sector, typically in viticulture, steep slopes are terraced with walls, so that one comes to even cultivated areas. Or, as in very many regions in the world where pasture farming is practiced, dry stone walls have been built to enclose the pastures. For example, the stone-rich island of Öland in Sweden - it consists of a huge network of such natural stone walls. The fenced areas are less exposed to the wind, wild animals can not penetrate, and at the same time for the construction disturbing stones were removed from the areas where crops were grown.

Vineyard on the Neckar in March, photo: pixabay

Dry stone walls - habitats

The open joints and cracks in the mortarless piled walls provide habitats for plants and animals with high heat requirements. In any case, they are something for adaptation artists. Typical wall dwellers are lizards, spiders, ground beetles and, for example, fire bugs. Also the stone bumblebee, which has become rare, needs such sites. Original sites in nature are rock walls and sun-exposed scree slopes.


Forest lizard (Zootoca vivipara) Photo: Christa Heners

Plants living in and on a dry stone wall also have to cope with chronic water shortage and temperatures of 50-60°C. Species of wall pepper (Sedum spec.) are particularly adapted to such extreme conditions, as are houseleeks or saxifrage species. The most sensible thing to do is to place the plantlets in the cracks with some soil connection as soon as the wall is piled up, and it is better to move them a little further back; if they stick out too far, they will dry out easily.
In time, more suitable seeds will fly in by themselves, and the diversity of species will increase. The base of the wall can also be planted, or you can sow a suitable mixture of drought-tolerant perennials (e.g.. "Heat-loving hem" by Rieger-Hofmann)


Roof houseleek (Sempervivum tectorum)

The best thing about a natural stone wall - it gets more beautiful as the years go by!

The beauty of dry stone walls, above all, is that unlike concrete or even plastic fencing, they get prettier as the years go by. Plants and animals populate the cracks and cavities, the stones show traces of wind and weather, and the top of the wall is a great place to sit and watch all the hustle and bustle.

A list of drought-resistant plant species adapted to these extreme conditions can be found at the end of the post.

Who of you now actually wants to build a full-blown natural stone wall in your garden, you are advised to delve a little deeper into the literature on this. The book "Dry stone walls for the garden" by Jana Spitzer and Reiner Dittrich, which is listed below in the literature tips, would be ideal for this in any case.

Natural stone wall in Småland (Sweden)

A few basics for building a mortarless wall:

• Materials are regionally typical quarry stones, e.g. limestones, sandstones, gravels...A wide variety of recycled materials can also be used to build a dry stone wall e.g. old patio slabs, concrete scraps, bricks,...
  

• A dry stone wall needs a foundation if it is to last for a long time. If piled directly on top of the soil, movement will occur in the structure as the soil freezes up and down, and it will inevitably shift over time.

For the foundation, dig a trench 30-50 cm deep along the entire length of the structure (depending on the height of the wall), in width the trench should be about a third of the height, plus 10 cm to each open side. Fill the trench only to about 10 cm below ground level.

• A vibratory tamper is recommended as a tool for the foundation. a hand truck for the stones anyway - and of course well-trained people who bring enthusiasm to the project. The lines can be achieved with the help of stakes and string.
  

• The wall requires a "run-up". That is, it is tilted backwards at an angle of 10-15°, so that it 'leans' against the embankment. You can also lay the foundation already in this way with a slight slope.
  

This principle applies when the wall is built against a slope. In the case of a freestanding structure, both side walls must taper upward in an "A" shape.

• In the case of a dry stone wall built on a slope, that is, when soil comes behind it, an air space of 20-30 cm must be left for the back lining. After each layer, the back lining, for which you can take gravel or crushed stone, is also filled and tamped a little. This layer serves as drainage and further stabilizes the wall.
  

• Stacking stones: Store the stones as stable as possible, so always with the largest surface down. Larger stones come down, smaller above. Nothing may wobble; if nevertheless must be wedged with appropriate smaller stones.

Every few rows the surface must be connected with long stones ('binders') and thus stabilized. Cross joints must be avoided at all costs, so always stagger the butt joints in the overlapping rows.


Sketch - Construction technique dry stone wall

If you would like to bring a structural element for heat-loving plants and animals in your garden, but do not yet dare to build a wall, you can also build a cairn or a stone pyramid. This is much easier, and also these elements with their joints and cavities provide hiding places, sunny spots and winter quarters for many animals. Incidentally, stone pyramids can also be planted, just like walls. To this special topic there is still another own contribution in the course of the year.


Lean site with cairn Photo: Henning Hinsenkamp

Further reading:

Trockenmauern für den Garten, Bauanleitung und Gestaltungsideen: Jana Spitzer und Reiner Dittrich, Publisher: ökobuch, 2019