PLANT USE IN THE GARDEN
Plants themselves can be important design elements, though few gardeners actually use them this way. If you have an artistic nature you can have great fun playing with where you put plants or how you prune them to bring out a certain look in your garden. The arching branches of a well-pruned cherry tree can frame an entire garden. The repetition of soft, grey-leaved plants or spiky foliage can be used as a theme in a long border. If you take the time to notice and experiment with the form, texture, and colour of plants, you will discover a whole new palette of design elements with which to work from. This is a three-dimensional consideration that takes into account the shapes and volumes of the plants in your garden. A variety of different forms make a garden interesting, but too much diversity creates visual confusion. Trees and shrubs have characteristic forms that should be carefully combined to avoid clashing. Flowers, too, have characteristic shapes: the rounded heads of alliums, verbena, and globe thistle; the vertical spikes of delphinium, snapdragons, and veronica; and the strong architectural lines of a large cordyline. Experiment by grouping plants with the same form into a drift, or by repeating a pleasing composition of different forms several times.
Texture: Plants have a tactile quality that can be used as a valuable design tool. Think about how the glossy leaves of holly, magnolia, and roses contrast with the suede-like foliage of lamb's ears, heliotrope, and coleus. Or how the fat and fleshy leaves of a sedum differ from the needle-like foliage of rosemary or the quilted leaves of a blue-green hosta. Flowers also provide textural interest. They can be rich and velvety like a rose, or as thin and translucent as a poppy. Even tree bark contributes textural interest - especially during the winter months.
Colour: Entire books have been written about using colour as a design tool. You can approach colour as a technician, using the colour wheel to create harmonious combinations, or you can use your own eyes and emotions to guide you in creating the look and feel you want. Combining colours in new and interesting ways offers a lifetime of exciting possibilities.
As a general rule, red, orange and yellow are colours that jump out at you. They are lively and stimulating, and give the impression that they are closer to the eye than they actually are. If you plant too many hot-coloured flowers, and don't balance them with cool-coloured, less assertive plants, your garden will be a jumble of blaring trumpets. Green, blue, and violet are cool colours. In the garden these flowers create a more soothing, restful feeling, and tend to recede into the distance.