I recently began work on a design to landscape the front yard of a La Jolla home. The current landscape is a throw-back to an earlier era, and most of the area is currently lawn that is bordered by an imposing hedge that tops thirty feet in height. The hedge stays for privacy. We decided on placing the weeping tree Peppermint Willow (Agonis flexuosa) to act as a focal point in the landscape that will effectively contrast with the tall hedge. The emphasis is on form and structure, bloom is taking a backseat in this San Diego landscape renovation.
Working with flower and leaf color in the landscape has been compared to painting a picture, working with plant form to sculpting a statue. Developing the right mix of plant shapes is as important in garden design as blending color. Each species has a basic form or structure, sometimes further enhanced or altered by selective pruning. Plants grow in dozens of shapes: tight and compact, open and airy, drooping, upright and cylindrical, and vase-like. And the list goes on.
Plant shapes need to be purposely melded into the design to complement and contrast size, shape, and structure. Mimicking the form of one species with another creates balance and draws the eye through the garden composition while altering or inserting opposing forms structural shapes sets up points and counterpoints that effectively draw the eye.
The overall shape of a plant is just one component of working with form. Leaf size, leaf density, trunk and branch structure, and bloom shape and size must be considered when mixing shapes. Certainly some plants stand out because of their dramatic shape and, when positioned for effect, create singular impact. Dracaena draco is a prime example with swollen a trunk and branches topped by rosettes of strap-like leaves. It would be a waste to set this plant in amongst a group of plants that do nothing to highlight its structure, or even worse, obscure it behind other plants. These striking plants need to be placed where they can be fully appreciated.
Plants of imposing structure can be equally as dramatic as those with beautiful blooms, with the added benefit that the plant with the striking form adds character throughout the year and not simply until the last bloom fades.