Just what constitutes formality, as usually understood, it may be well here to discuss. It may arise from several causes. Unquestionably the most common one is symmetry in the general lines of the design.

Another cause may be injudicious planting, particularly when the gardener has not adopted means of building up a well-considered picture in the vertical plane. Such mistakes only need to be recognized to be corrected.

Trees planted sentinel-wise, at equal distances from a central feature, will produce a formal effect. They would be better arranged so that no two subtend the same angle in the line of sight. The repetition of some conspicuous feature at regular intervals also makes for formality, an error not infrequently made in planting with conifers and other evergreens.

Complexity in detail may suggest formality, by proclaiming too insistently the artificial character of the garden. Still another cause is neglect to preserve a proper scale in the various details. It might be concluded that the use of straight lines and right angles would lead inevitably to a formal result. Proper use of garden planters can assist in forming straight lines and right angles.

Such is not the case. On the contrary, in small gardens the use of straight lines, in combination with a studied simplicity of treatment, is the most efficient means of securing an informal result, because it enables the designer to harmonize his plan with the shape of the garden boundaries.

On the other hand, the use of curved lines may only serve to render too conspicuous the rigid outlines of these boundaries. It must here emphasize the value of variety - variety in outline and variety in shape - as opposed to too frequent repetition of similar shapes, and variety in planting so as to secure a good effect in the vertical plane.

Such variety must be carefully throughout, and made to give character to the garden as a whole. This does not imply over-elaboration, nor is it opposed to simplicity of treatment. It is just the avoidance of undue repetition of lines and shapes.

Another factor in the attainment of the picturesque is what I may term "reticence." It is not well to aim at giving too comprehensive a view of the garden from any one point. The planning should be so contrived that the various garden features are seen one at a time as it is traversed from end to end.

This may be arranged by judicious screening, for which trees, shrubs, arches, trellises, and other objects may be employed. Much may be done in the planting to attain this very desirable quality. A long herbaceous border filled with flowers carefully graded in height, the tall ones all standing at the back and the short ones in front, presents a rather monotonous vista.

Its charm is greatly enhanced if the process is partly reversed, so that here and there a bold clump of flower or foliage is allowed to push forward, thereby screening what lies beyond; and incidentally this arrangement has value in affording shelter to the smaller and tenderer plants lying between their robust companions.