There are a number of things to consider in landscape design, from the aesthetics of the finished product to the utility of the garden. By thinking about these issues ahead of time and coming up with a coherent plan for a garden or landscaped space, gardeners will be able to create a project which is more pleasing in its finished incarnation. Landscape designers can command hefty fees for their expertise in their matters, but much of landscape design is actually common sense.
When landscaping a space, it's a good idea to think about limitations first. Space is an obvious limitation, but so are issues like water availability and the climate. Finding out your climate zone can be a big help, as can exploring the area to see what kind of condition the soil is in. If the soil needs to be amended for certain plants, it's good to know this ahead of time.
Because landscape design is supposed to create unity between a human environment and a natural space, when considering limitations to landscape design, you should also think about the setting. Sketching out the space and including landmarks like structures, hills, big rocks, and large natural features such as trees which you would like to keep is a good idea. You should also think about the lie of the landscape, because mountains, valleys, forests, lakes, rivers, and other natural features can interplay or clash with landscape design, depending on how the design is handled.
You should also think about the feel of your garden. Some gardeners, for example, like to plant very wild-looking gardens with natural plants which integrate seamlessly with the natural environment. Others like old-fashioned gardens, formal gardens, or more modern gardens. You may want to explore the neighborhood to look at other gardens and think about how they make you feel, and which ones appeal to you. Gardens with native plants can be more environmentally friendly, because they require less resources and reduce the risk of spreading invasives, while formal gardens can be very high-maintenance, due to higher water and fertilizer requirements and the need to keep down weeds.
Texture, color, scale, form, and line are all critical aspects of landscape design. Texture refers to the visual texture of plants. Some plants, for example, have very jagged, weedy looks, while others are smoother, and interplaying these textures can provide a distinctive look. Color can be manipulated with flowers, foliage, and rocks, while scale or proportion refers to the size of various plants, and to the interplay of size. A monstrous tree, for example, would look ludicrous with some tiny primroses underneath it, while a dense planting of lavender might look stunning with a border of low shrubs.
Form has to do with the shape of plants, and how they fit into the visual landscape, while the line involves the literal lines of the garden. In a hilly landscape, for example, a garden composed of only straight lines would feel very jarring, while curved paths and sloping beds would fit in with the natural landscape. Strong geometric shapes pair well with modern and formal gardens, while rigid lines and boundaries tend to clash with more natural landscaping styles.
Another consideration in landscape design is features. If you have a deck, for example, you may want to surround it with plantings which frame it, creating a bridge between the house and the outdoors. Lakes and streams may be highlighted or minimized, depending on how the landscape design is arranged, and it is easy to create hidden corners in a landscape with the use of screening plantings and meandering paths. Some people like to design a garden around a focal point like a lawn, a statue, or a natural feature, while other people prefer to draw the eye away from ugly structures like sheds.
It is also important to think about how the garden will be used. Some gardens may be used for recreation, for example, while others are purely aesthetic. Gardens used to grow crops can be every bit as beautiful as purely ornamental gardens, and gardens designed to screen out unsightly views require features like hedges and tree lines. Seasonal uses are another consideration, as gardens change radically through the seasons. If you like to entertain in late fall, for example, you may want a garden with plants which look good year-round, rather than plants which reach their height in the summer.