What determines formality? Formality can arise from several different causes. The most common is symmetry in the general lines of the design.
Another cause is imprudent planting, especially if the gardener has not adopted means of building up a well-considered picture in the vertical plane. These mistakes are easy to correct once they are seen and understood.
Trees planted sentinel-wise, at equal distances from a central location, create a formal effect. The trees would look better planted so that no two subtend the same angle in the line of sight. The repetition of some conspicuous feature at regular intervals creates formality, a common error with planting conifers and other evergreens.
Complexity of details may suggest formality, by focusing on the artificial character of the garden. The neglect to preserve a proper scale can also become an excuse. It might be concluded that the use of straight lines and right angles would lead inevitably to a formal result.
On the contrary, in small gardens the use of straight lines, in combination with a studied simplicity of treatment, is the best way to create an informal setting, allowing the designer to harmonize his plan with the shape of the garden boundaries.
On the other hand, using curved lines can make the rigid outlines of these boundaries appear much more to the eye. Variety needs to be outlined in this is the case, variety in outline and variety in shape, as opposed to similarity and repetition.
Such variety must be carefully throughout, and made to give character to the garden as a whole. Variety does not mean to over-elaboration, nor is it opposed to simplicity of treatment. It is JUST avoiding the repetition of the same 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 idea behind this is to create a painting, where the eye takes in the whole view before focusing on any one particular aspect.
This may be arranged by judicious screening, for which trees, shrubs, arches, trellises, and other objects may be employed. You can do a lot with planting to create this 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. This type of arrangement will also provide shelter to the smaller and feeble plants lying between their robust companions.
