Plants with horizontal, or spreading, form can serve many purposes in garden design. At first they may not seem as dramatic as a strongly upright or globular plant, but with a second glance their interest and value becomes apparent.
When choosing a plant to add to your garden, it's always a good idea to consider one with an intriguing or unique form or shape. Though we tend to gravitate toward plants with eye-catching flowers or colorfully patterned leaves, form offers longer-lasting interest and contributes much to the overall garden design. Plants with horizontal form add a soft note that can link together companions with stronger, starker shapes. The sideways growth habit also provides a sense of motion, directing our sight from one part of the garden to another. Options exist for all layers of the garden, from the ground to the canopy.
Low plants with a mat-like or spreading form help ground the garden to its site, much like the carpet does to the furniture in your home. Examples include shrubs like creeping juniper (Juniperus horizontalis cvs.) and bearberry cotoneaster (Cotoneaster dammeri) and creeping perennials such as lamb’s ears (Stachys byzantina).
Mid-size shrubs and small trees with spreading branches create a unifying, yet contrasting, middle layer in the garden. Their shape is particularly lovely when it’s placed in front of taller upright or vase-shaped trees. Doublefile viburnum (Viburnum plicata var. tomentosum) and pagoda dogwood (Cornus alternifolia) are two woody plants with exceptional horizontal form.