The shape of the garden is defined by the shape of the ground, the walls, hedges and fences that divide it up, and the plants that decorate it. The basic shape of the garden, formed by the ground shaping and hard materials, must be pleasing in its own right before any plants are added.
For example, a garden site with slopes, terraces, ornamental walls, trellis, water feature, and paved areas would be interesting before any plants are put in.
Although the shape of plants is their most important ornamental feature, it is usually the one least taken into account in choosing them for the garden. The characteristic outline of each plant is unique and ought to be considered carefully. The various shapes should be used in combination to create interesting pictures.
Using plant shape – Plant shapes vary from horizontal (prostrate on the ground) to vertical (narrow upright pillar). The other plant shapes are between the extremes. Rounded shape, for example, has about the same amount of each dimension, tall as wide. The shape of plants can be used in two ways; to accentuate similar shapes, or to contrast with opposites.
When using plants to accentuate the shape of other garden objects, the idea is to ‘pick up’ the dominant lines of the shape to be emphasised. The horizontal lines of the roof of a house might be mirrored by flat-topped trees or shrubs at a different level.
Trees of columnar shape could be used to emphasise the vertical lines of the house walls. For example, a flat-growing conifer placed at the corner of a house contrasts with the vertical of the wall, while a small tree of columnar shape emphasizes it.
Many plants are of rounded, or conical shape and these are very useful for contrast with the rectangular shape of houses, walls, fences, trellis, paths and paved areas. Rounded and conical shapes are of varied height and width.
Considerable added interest can be built into the design by using various rounded, or conical, shapes in association with each other. Since so many plants are of intermediate rounded or conical shape, this effect usually happens when choosing plants for other reasons, but it is no harm to bear it in mind.