The eye follows garden lines such as edges of a walk or the curve of a flowerbed. The character of a line creates a mood. Gentle, slow curves and horizontal lines are seen as restful while jagged diagonals or vertical lines create excitement and tension. Shapes defined by lines are the most readily seen aspects of a landscape. Plant shapes divide and define the spaces in the garden.
Some forms are more dramatic than others and attract attention.
The form of the plants selected and their placement are critical to creating comfortable spaces. Rough, coarse textures are informal and visually dominant, while fine, smooth textures have a more formal, elegant feeling. Coarse leafed plants such as leatherleaf mahonia offer a dramatic textural effect against rugged stone. A fine textured plant such as boxwood may look better with a more refined material such as a smooth brick. Use more than just one type of texture to avoid lack of interest.