Annual flowers play an undeniably important role in ornamental gardening. Trees and shrubs can supply flower color at a height that is usually from eye-level upwards, while herbaceous perennials, like annuals, flower at a height ranging from ground level to about a meter. (3ft) While by no means essential for a successful garden, annual plants nonetheless fulfill a number of needs.
Firstly, they supplement the perennials in a garden bed. As it is virtually impossible for a perennial border to look good at all times – plants need to be clipped, pruned down to the ground, or lifted, divided and replaced – annuals fill the inevitable gaps, while providing color and interest at the same time.
Secondly, specific color effects are sometimes only attainable by using annual bedding plants. It is difficult to think of perennial equivalents to the deep red of some Petunia varieties, the staggering purple of some Lobelias, or the bright orange of marigolds. (Tagetes) Furthermore, despite needing to be replaced every few months or so, annuals often involve less work than maintaining a perennial flowerbed. It is with good reason therefore, that annual flowers are sought after by home gardeners, designers, and landscape professionals alike.
The main problem in dry climates is the very high use of water that annual plants demand. In Mediterranean climates, summer annuals need at least 1000 liters per square meter per year of irrigation water. By way of comparison, perennials like sage can perform perfectly well on less than half that sum. Here then are some guidelines for enjoying the beauty of annual flowers, while keeping within water limits.
- Concentrate flowers, both annual and perennial, in one or two special spots in the garden. This creates a strong design, as opposed to “peppering” them throughout the garden. Together with this, a separate irrigation line should be provided for the bedding plants. It is impossible to take advantage of the low water consumption of many shrubs and trees, if annual flowers are planted around them.
- Try to think of color schemes as one would when planning a sitting room, or deciding on what to wear for an evening out. There is nothing “natural” about randomly throwing different colors together. It is simply bad taste!
- The use of summer annuals should be restricted as far as possible. It is often best to limit them to pots and containers, placed strategically in front of water conserving shrubs, which act as a background for them. An exciting effect can be achieved by just a small group of red flowers in pots, against the green of a hedge.
- In Mediterranean climates, the winter is the also the rainy season. A large range of winter annuals are available to the gardener, and can be grown almost without resorting to watering at all. They can also be planned to coincide with the flowering of bulbs and corms like tulips, daffodils, and hyacinths. In order to save water therefore, winter/spring, and not the summer, should be considered the primary season for annual color.