Using retaining walls in your garden

Beautifying your garden by building a retaining wall, behind which there is a lawn or an expanse of flowers, is not a difficult task. But, like all garden problems, it requires some effort and care.

The retaining wall must be strong enough to contain the pressure of a large weight of soil, yet porous enough to allow drainage.

The most popular types of walls are built of stone, either lined or rubble. When using stone for a retaining wall, there are two basic types of construction: drywall, which uses earth as a filler between the stones, and mortar, which uses cement as a bonding agent.

The base of any retaining wall must sink below the frost line. This is about 6 inches in the northern half of the United States.

For a flat wall (one without buttresses or overhangs), the width of the base should be equal to one-quarter the height of the wall. The wall can be shortened to a width of about a quarter of the width of the base.

For buttressed walls, the base should be one-fourth the width of the wall. This refers to the widest points where the buttress will be used. In narrower areas, the base may be thinner in proportions.

retaining wall

At intervals of approximately 24 inches and approximately 6 inches from the lowest ground level of the retaining wall, the drain pipes should be recessed into the wall.

On some walls, if the wall itself is porous enough, these drains can be removed. But in any construction that uses mortar as a binder, these drain pipes are a must.

In dry wall construction it is possible (although not recommended) to start at ground level and not sink the wall below the frost line.

The most economical way to build a dry wall is to choose local stone, choosing large stones for the main stones and smaller stones for the cracks. Larger stones should form the base of the wall and smaller stones should reach the top.

The outward facing side of the wall should be as level as possible, with obstructions and outside stone edges facing in.

This not only gives the wall a better grip on the ground that it retains, but also ensures a good appearance. Stones with round surfaces should be discarded as they do not form a good wall.

stone retaining wall

The stones must be placed well adhered. This simply means that the edges of the stones in one row should overlap the gaps in the bottom rows.

When a stone in an upper row is crooked or does not fit firmly, dirt and small stones can be packed to improve the bond. No vertical cracks should be left.

The wall itself should lean back against the ground it is holding. This gives it added strength. The width of the base of the wall should be, again, as a general rule, one-third of the height.

It is practical in many areas to tilt the wall up to 5 or 6 inches for every vertical foot, although this degree of tilt is not essential. The soil must be tightly packed into all wall voids and continued back to the soil to be retained.