All effective landscape designs rely on basic principles. An understanding of these principles can keep you from creating a landscape beast instead of the beauty that you dream about. Unity, simplicity, variety, balance, sequence, and scale are terms often associated with art. These terms are used to guide an artistic expression, and in landscape design they are just as important as in other art forms.
Unity describes the idea of tying the landscape together into an orderly design.
Different parts of the landscape should relate to each other. You should get a sense of visual flow from one part of the landscape to the other so that features of one part remind you of another. Some repetition of a feature of the landscape is good, but it should not be carried to the point of monotony. Unity in the landscape can be achieved through a theme of colors, forms, or textures without using exactly the same plants. For example, a red color may be used as a theme, but you could use plants with reddish foliage as well as other plants with similar colored flowers or foliage.