Perhaps the one aspect of gardening that excites me the most is the aspect of color and its use in gardens and landscapes. This is a complex topic, but the basics are fairly simple. By knowing these, you can create various effects in your own garden.
To begin, do you know what color really is? This will vary depending on whether you are an artist, a photographer, an electronic graphic artist, or a printer. Suffice to say here, that in all but art, color deals with light--both absorbed and reflected--and is composed of three basic colors, plus black in the case of printers. Since garden design with color is most closely related to art, let's explore this view of color.
Most people are familiar with the artists' color wheel, with the six main colors of the spokes or pie slices of the circle. The three primary colors are red, yellow, and blue. Combine these, and you get the colors in between-- the secondary colors. So red and yellow make orange, yellow and blue make green, and blue and red make purple.
The effects these colors give in an "outdoor room" or garden space or bed are the same effects you can achieve indoors. The colors on "top" of the wheel-- red, orange, and yellow--are the "warm" colors. The others--green, blue, and purple--are the "cool" colors. Warm colors are just that--they give a feeling of warmth, security, or to the extremes hot, passion, and excitement. Cool colors give the opposite effects--calm, serene, relaxing.
Most gardens should have no more than about 10 to 15 percent of really warm or hot colors for best design. You can use more warm-colored plants and flowers than this, just fewer in number than the cool colors. In other words, perhaps a group of three red flowers among a bigger group of 20 to 25 cool ones, or several different varieties of cooler colors.
Keep in mind that the main color of gardens and landscapes is green, a cool color. Often, the effect of cool colors can come mainly from foliage and lawns and leaves of woody plants. These form the "background" of landscapes.
Warm colors tend to "advance" or be closer than they really are, so use them to draw attention to parts of a garden or landscape, to make parts of gardens appear closer. Cool colors tend to "recede" or be farther away than they really are, so use them to make parts of the garden seem farther away, or be not too noticeable.
White deserves special mention for its use in gardens. It is a good example of the difference of light and art color theory. If you put all the colors of light together, white is formed. Yet in art, combine all the main color pigments and what do you get? A muddy gray.
White draws more attention than even the warm colors, so use it sparingly, use it to contrast with other colors, to separate colors from one another, or just by itself. Examples of the latter are white gardens and moon gardens--those that show up at night in moonlight or with low lighting. White--either flowers or white variegated foliage--is also good to use in shade to brighten up the area a bit.
Follow these basics when choosing flowers for your garden, and you're on your way to good design. As with any rules and principles, there are exceptions, and you can have attractive designs with striking effects such as a riot of mainly warm colors, as long as this is the effect you are trying to achieve!
Consider, too, the color of the foliage and how it will look in your garden when shopping for perennials and some of the newer vegetable varieties.