For this reason an understanding of colour is important if you want to get the best out of them. This does not mean having to learn a list of rules on what goes with what and how to avoid colour clashes, never put shocking pink next to orange and so on. These purist rules are less important in the garden than is often supposed. The reason is quite simple. A solid sheet of colour placed directly next to another with which it clearly does not harmonize can be distasteful and this does occur in interior decoration, dress etc. In a garden however, the various hues, shades and tints are broken up by the green foliage and earthen shades which dilute the so-called colour clashes.
The purpose of this section is to show you how to make colour work for you in the garden and the basis of colour theory is the classic wheel shown below.
As you can see there is a basic division into warm and cool colours. To make a plot look longer, plant warm-colour flowers as close as you can to the point from which you view the garden and put the cool-colour varieties right at the back. The weather has an effect on the appearance of flowers. Pastel shades can look quite washed-out in brilliant sunshine but their colour is heightened on dull days.
Within this broad span of warm and cool colours you will find a number of individual hues. There are basically three ways of harmoniously putting these hues together. The boldest way is to match contrasting colours, the most restful way is to match colours which lie next to each other on the wheel and the most subtle way is to use tints and shades of a single hue.