Garden Walls Can Be Beautiful

How many suburban places today could have their general appearance improved if the masonry walls flanking the driveway or turn-around, or the walls enclosing the terrace, were converted into wall gardens? How many hours of strenuously pushing a lawn mower up and down steep slopes could be saved, were the lawn graded into several levels separated by planted retaining walls? Such walls are just as useful, and so much more attractive.

As in every form of gardening, there is a right and wrong way to build a wall garden. It does take more thought, time and labor than just “to pile stones together.” The latter haphazard method may suffice to mark the boundary of pasture land, but it does not furnish good growing conditions for plants.

Here in the eastern states, and in other sections, where the problem of alternate freezing and thawing exists, it is well to make a solid base – excavating two feet deep and two and a half to three feet wide along the length of the proposed wall. Broken pieces of rock, small stones, coarse gravel, and soil, fill the excavation to ground level. The soil should be firmly packed – playing the hose on it will force it down among the rocks where it belongs.

The first layer of rocks is then placed on this foundation and should reach back into the hank. Soil is pressed in and around the rocks to fill all spaces. This is important throughout the building of the wall, for air pockets mean death to plants.

In setting the rocks, be sure they tilt downward at the rear in order to direct the moisture to the back of the wall where most of the roots will be located. Also, as the wall gains in height, the face recedes approximately one inch to every foot. Assuming the wall is four feet high, the top row will be four inches back from the front of the base. This backward slope is to catch the rainfall needed by the plants.

Most of the plants which adapt themselves to wall gardening like a neutral soil. A satisfactory composition consists of one part good loamy soil, one part sand, one part leafmold, and one part well-rotted cow manure. And I mean well-rotted; otherwise as it ages and loses bulk, air pockets may be created in the rock crevices. Some plants, for example Dianthus, Sedetms, and Sempervirums, like a leaner, grittier soil so that crevices accommodating them can be filled accordingly. Other plants may indicate a preference for acidity and their taste may be gratified with the additions of acid peat moss or oak leafmold.

With the first layer of rocks ,covered with about two inches of the soil mixture, planting begins. The roots, spread out carefully to their fullest extent in a little hollow made by scooping out some of the soil, are then covered with soil and patted firmly. The crown of the plant is level with the face of the rock below it, with the roots running to the back of the wall. The planting continues in this manner until the length of the wall has been completed. Then the second row of rocks is laid on, covered with stones, and the plants set in. The procedure continues until the whole wall is finished.

Field-grown or potted plants may be used, but the latter are more easily handled, as their root systems are compact. There’s another advantage with potted plants in that they can be planted almost any time of the year except in the hot months of July and August. Planting can even be carried out in those two months, if necessity dictates – but neither the plants nor the planter really enjoy the operation.

The choice of plant material is determined, to a large extent, by the wall’s exposure – full sun or partial shade – and by the kind of stones with which it is built. If the wall is constructed of weathered rocks, diminutive plants which peer out of pockets and crevices, with trailers here and there, would be a reasonable selection. On the other hand, if the stones are more or less ordinary, and were used because they were readily obtained for a retaining wall, the logical thing is to conceal them as much as possible with trailing and mat-forming plants.

Continued – Choosing Plants for Wall Gardens

by D Ebell

Related Articles Of Interest:

• Building Wall Gardens – Strength beauty and Style
• Using Retaining Walls in Your Garden
• Landscaping Stones – Wide Assortment of Sizes and Colors
• Wall Gardens – Choosing Plants