at the
top, a strip of earth should be left and there a wider variety of plants
can be grown. Single Marguerite carnations and grass pinks will form a
sort of cascade of foliage and bloom there if planted close to the wall
or in the crevices of the top, and a similar effect, but much bolder,
can be created with the perennial pea (_Lathyrus latifolius_).

If the dry wall is already made, the crevices can be plugged with soil
if care and patience are used. Even a cemented wall is not hopeless;
here and there the mortar can be chiseled out and an occasional small
stone should be removed.

A wall garden has these advantages over a rock garden; it is more easily
constructed, it is of practical use, and it is sometimes a possibility
where the other is not.

WATER AND BOG GARDENS

Neither the water nor the bog garden is dependent on rocks. Either or
both, however, may just as well be an adjunct of the rock garden. They
solve the wet spot problem admirably, permit the culture of native water
lilies, orchids, and numerous other beautiful plants, and certainly
contribute their share of picturesqueness. If water is lacking, it may
often be introduced at little expense.

[Illustration: A little grotto with trickling water makes a picturesque
break in a wall garden. If shady, plant ferns generously]

In most cases it will be found that some cement construction is
necessary, but not a bit of it should show. This is easily managed by
building a cement shoulder on the sides of the pool or stream a little
below what will be the level of the water, and then setting rough stones
on that. A cement bottom for shallow water may be disguised by
imbedding pebbles and small stones in the cement before it sets.

[Illustration: To conceal the cemented bank of a pool or stream, make a
shoulder eight inches or so wide and about six inches below the water
line. Then place small rocks on the shoulder]

Dispose the rocks very irregularly, but they may be so few as to be mere
notes. Avoid stagnant water, and if mosquitoes are feared introduce some
goldfish. They like mosquito larvae.

Water lilies and sagittaria--one plant will do if the pool is small--in
the water and near it, but not in standing water, Japanese iris, yellow
flag, globe flower, and _Lythrum roseum_ are good selections.
Forget-me-not is one of the finest plants for the banks. Use the
perennial kind (_Myosotis palustris semperflorens_).

The bog garden simply reprodu