BUILDING A DRY WALL

Press, Volume XCIX, Issue 29389, 16 December 1960, Page 11

BUILDING A DRY WALL

—A Job For The Holidays

Not everyone is blessed with the sort of section that has varying levels. It is the type of asset that should be carefully conserved, for a few ups and downs in a garden make a world of difference to the general appearance. Steps leading from one level to another can be used as an interesting feature to look at, if carefully built; a graded bank with prostrate conifers sprawled over it make an Informal division; and a dry wall can give a more formal dividing line. Even on a completely flat section a dry wall can be used One garden I know has. an attractive little courtyard using a dry wall, battered on both sides and with soil in the centre, as a boundary wall all round. The use of this garden feature is limited only by the extent of your imagination. A dry wall,,of course, is a wall in which no mortar or cement is used. The bonding of the stones is achieved by careful placement, so that the weight of the layers above prevents movement below. A slight batter is also needed to give a cant to the rear. If, for example, the wall is three feet high, then the top course is normally six inches out of vertical from the bottom cdurse. This batter also helps to make the wall a firm one.

The function of a dry wall is not just to enable you to save the cost of cement—it is to provide a suitable planting place for trailing plants, or those which like vertical crevices. Ideally, the wall is planted at the same time as it is built, but I am inclined to regard this as advice more commonly given than carried out. Certainly there is a good deal to be said for the practice—if it can b2 put into effect. Most of the plants which you use for dry wall planting will have been

grown in three-inch pots, if you buy them from a nurseryman. It is rare to leave a crevice as wide as this, so that “planting” in the face of the wall is exceedingly awkward with a root ball of this size. Hence the advice

to plant and build together. But if you are juggling with a great lump of stone, a straight edge, a line and a plant all at once, then I know which you are most likely to put down first—and probably tread on as you stand back to admire the effect!

The type of stone required for the job is "dressed two sides,” that is, it has got approximately parallel upper and lower surfaces. Get it dumped as near to the work as possible—the less carrying the better. Excavate a shallow trench about six inches deep to hold the foundation firm. Then, using 2 by 1 timber, peg a footing board in position to act as the guide for the lower end of the straight edge Using pegs to give you a finished height about six inches higher than the height of wall intended, drive these in in front of the footing board. Nail cross pieces to the upper ends of these pegs, using the length required to give the correct batter to the wall. If a top board is then nailed to these cross pieces you have an excellent support for the straight edge, to give a true wall face. This will save much fiddling with lines, which always seem to get out of true—at least they do with me, an. way.

You’re now ready to build the wall. The skill is in choosing your stones carefully so that they sit nicely, don’t rock, and have no tendency to skid out at the front. Lean the stones very slightly back to give the required batter to the wall face. Fill the back, between the bank and the

wall, with soil as you go, and It is also a useful dodge to set one or two long stones from the bank to the wall face as you go. This will make the wall a little firmer. But make sure that the filling soil at the back is rammed as firm as it can be, or you will have trouble later, particularly if you have used dry soil, which is more difficult to firm. Damp, but not wet soil is best.

Leave gaps between adjacent stones on the same course for planting (if you are not doing it as you go). These should be about 12 or 15 inches apart along the wall, but staggered slightly, some at higher levels and others lower down. Unless the wall is a tall one, or you are intending to use compact plants (most wall plants are relatively vigorous) it is a waste of time to put one planting hole above another one, for the upper plant invariably swamps the lower. Use the straight edge so that the wall face is reasonably true, but slight irregularities will not be noticed once the plants grow A bucket or so of good compost will be required for planting, and the root ball tightly plugged in position with it, using a piece of broom handle about an inch in diameter for firming. If the soil behind the wall is moist, and also the root ball and compost, then no difficulty should be experienced in getting plants to grow away this season. If your plants are well chosen a rock wall can give you pleasure for several months of the year.