Garden design is the creation of plans for layout and planting of gardens and landscapes. Garden design may be done by the garden owner themselves, or by professionals. Most professional garden designers are trained in principles of design and in horticulture, and have an expert knowledge and experience of using plants. Some professional garden designers are also landscape architects, a more formal level of training that usually requires an advanced degree and often a state license. Elements of garden design include the layout of hard landscape, such as paths, rockeries, walls, water features, sitting areas and decking, as well as the plants themselves, with consideration for their horticultural requirements, their season-to-season appearance, lifespan, growth habit, size, speed of growth, and combinations with other plants and landscape features. Consideration is also given to the maintenance needs of the garden, including the time or funds available for regular maintenance, which can affect the choices of plants regarding speed of growth, spreading or self-seeding of the plants, whether annual or perennial, and bloom-time, and many other characteristics.
The most important consideration in any garden design is, how the garden will be used, followed closely by the desired stylistic genres, and the way the garden space will connect to the home or other structures in the surrounding areas. All of these considerations are subject to the limitations of the budget. Budget limitations can be addressed by a simpler garden style with fewer plants and less costly hardscape materials, seeds rather than sod for lawns, and plants that grow quickly; alternately, garden owners may choose to create their garden over time, area by area.