Such a rock garden, large or small, is a complete unit in itself. Within its own limits, of course, it must be made to look as natural as possible. Beyond that, it is just a special type of garden occupying a place in the general landscape scheme.
On the other hand, the attractiveness of the rock garden, even though it be an entirely artificial creation, will be greatly enhanced by giving it a setting or background of a type which will make more gradual the break between the rock garden itself and the lawn and the balance of the landscaping. This subject is discussed further in a later chapter.
The Natural Rock Garden. Fortunate, indeed, is the home owner who possesses the nature-made foundation for a rock garden. This may be in the form of an outstanding ledge of rock, a stony bank or slope, a small ravine, or it may be but a hollow or an irregular contour which, with the addition of stones, will look wholly natural. In any event, he finds himself in possession of that which even elaborate planning and the expenditure of a large amount of money cannot duplicate if it is not there to start with, and which will make it possible for him to have easily what is one of the most beautiful and, at the same time, one of the least expensive forms of flower gardens to maintain—a genuinely natural rock garden.
The Wall or Bank Garden. Still another form of rock gardening is that in which a rock wall may be utilized for the growing of rock plants. This makes it possible to have a rock garden in the least possible space, and such a wall may almost always be made to look as though it belonged, even though it may have been placed there for the specific purpose of growing rock plants. Very often it is possible to convert a steep terrace, which it has been difficult to make and difficult to maintain in sod, and which has been unsightly if not positively ugly, into a beauty spot which will attract more enthusiastic admiration than any other feature of the place.
By the use of some suitable perennials in addition to alpine and rock plants, a wall or a rocky bank may be kept colorful from one end of the season to the other. The opportunity for this type of rock gardening is probably the most generally overlooked of any. Not infrequently one sees large sums spent in eradicating or destroying banks, or putting in solid masonry walls, where a suitable wall garden might have been created at a much smaller cost. (See accompanying illustration.)