How deep must a lawn edging stone be embedded in concrete?

Hi,

I want to set a lawn edging stone as a boundary on the slope. On one side it should stick out a bit, on the other side a small path should run flush with the top edge. In other words, a step should form along the edge. A step height of 20 cm would be desirable.

The cheap standard stones are only 25 cm high. But they are mostly available in 30 or 40 cm height as well.

The question is: how much of the edging stone must be concreted/in the ground on both sides to ensure it holds.

I have already seen many pictures where edging stones are used as step borders for platforms or stairs in the garden. The steps then also stand freely 15 cm high and visible from the front side. Or flower beds next to the lawn, where the beds are at least 10 cm higher than the lawn and the edging stone can be seen on one side.

Is there maybe a rule of thumb that 1/3 or half of the stone must be fixed so that it holds? If I were to use a 40 cm stone, maybe 20 cm deep concreting would be sufficient?

Thanks, best regards

Is there maybe a rule of thumb that 1/3 or half of the stone must be set for it to hold?

Everyone does that a bit differently, but your 1/3 is a good guideline.

Between 1/3 and 1/2

I agree with the previous writers. However, it also depends on the usage. Lawn to flower bed is uncritical, lawn to step is rather a heavier load.

I agree with the previous writers. However, it also depends on the usage. Lawn to flowerbed uncritical, lawn to step rather more stressful.

just a small edge path that is walked on <10 times a year to do pruning. Not even wide enough for a wheelbarrow. I think I will then settle on half to be sure. Thanks.

I think I will then settle on half to be safe.

I am known to be conservative – it already seems quite bold to me to only dig in half the height with one-sided earth pressure. I’m thinking of lever forces, and the fact that compared to the L-stone, the edge stone is practically an I-stone.