Depending on the space and the amount of time you are able to put into building a garden, you might need to confine your rock garden to a single bank that lies against a fence or a water wall fountain. If this is so, it would be a good idea to clothe the artificial background with ivy or other creepers.

The rock garden should never come to an abrupt end. It is best to let it gradually merge into the general surface of the ground, with some detached pieces of rock being placed on the level beyond the raised part of the rock garden, just as you would find in nature.

Many alpine plants will thrive perfectly well on the level, if they are protected from the encroachment of coarser plants. Thus these outlying rock pieces may be enshrined in masses of phlox, aubrietia, or dianthus, which, unconstrained by any rocky limits, will spread into wide cushions of color.

You should learn to know your plants by sight; don't label them. The appearance of a labelled rock garden in the spring, before the plants have put forward their foliage, is depressing, and reminiscent of an auction room.

In wall gardens, Mother Nature has shown how she can clothe an old vail with her treasures. When the plants are naturally established, they often display a charming habit in adapting themselves to their artificial home.

Who has not seen a ruined wall topped with pinks, or with snapdragon, toadflax, and sedum, or hung with the charming grey foliage and glistening white flowers of cerastium? Such a picturesque display is not difficult to copy, but you need to have the right kind of wall. This would not be the new, neatly pointed red brick affair, but a thing of cracks, crevices, and crannies, such as you would find enclosing some old country garden.

This is especially true if there is an attractive landscape beyond. The character of the immediate environment should determine both the height of the fence and the design, which may be open, closed or a combination of both.

Such a scene is easy to create. We have only to rub some fine soil into the chinks and to sow the seed of such plants as we desire, covering them up with soil to prevent the birds abstracting them, and in due course we shall have our colony of alpines.

If no wall exists, then you should build one, and in doing so you can make provision for as much plant life as you plan to have. The wall may be of concrete, rubble, rough stone, or old bricks. Of these, the best are the last three. However, unless ample spaces are left between bricks, there will be difficulty in finding sufficient lodgement for the plants.

Stone and rubble, using irregular blocks, would give opportunity for earth pockets and crevices of various sizes. There should be no pointing, and only so much mortar used as is necessary to secure stability.

Large spaces may be filled with the compost recommended for the rock garden and then sown. The smaller crevices may be filled with soil mixed with the seeds. Autumn is the best time of the year to plant seeds for flowers in the rock garden.