The creeping and trailing rock or alpine plants and small or prostrate shrubs or evergreens, can generally be used to especially good advantage in natural rock gardens with large stone surfaces.
The Terrace Rock Garden. Where a steep slope or terrace is present to begin with, an effective and beautiful rock garden may usually be made more easily than under any other conditrons. The chief difficulty here is to avoid a stilted and artificial-looking job.
Be sure to bury the stones deep enough so they will not look merely "stuck on" the surface. And by all means do not allow a smooth, even grade, such as would be desirable if the bank were to be sodded; your gardener or workmen will be sure to finish with just such a grade if you do not prevent them. Care must be exercised, also, to use stones sufficiently varied in size and shape. The filling between the stones, especially the four or six inches at the surface, should be prepared soil.
The Wall Garden. This type of rock garden is perhaps the most generally overlooked of all opportunities for utilizing rock plants. At trifling expense, many an unattractive if not positively ugly wall may be converted into an object of Aston shing beauty, with literally breath-taking masses of color for many months of the year.
Where a wall is to be used for the growing of plants, it is far better to construct it with this object in view than to attempt the adaptation of an old wall. The soil behind the latter is almost sure to be unsuitable, and also to be too hopelessly dry even for rock plants. However, much may often be done in the way of planting along the top of an old wall, using varieties which will trail over or form hanging mats; and a few pockets may be inserted in the upper part of a wall, where it is possible to get some moisture into the soil back of it.