shelter from strong winds and provide micro-climates, to screen unattractive structures or views, and to create an element of surprise. Surfaces In temperate western gardens, a smooth expanse of lawn is often considered essential to a garden. However, garden designers may use other surfaces, for example those "made up of loose gravel, small pebbles, or wood chips" to create a different appearance and feel. Designers may also use the contrast in texture and color between different surfaces to create an overall pattern in the design. Surfaces for paths and access points are chosen for practical as well as aesthetic reasons. Issues such as safety, maintenance and durability may need to be considered by the designer. Gardens designed for public access need to cope with heavier foot traffic and hence may use surfaces – such as resin-bonded gravel – that are rarely used in private gardens. Planting design Planting design requires design talent and aesthetic judgement combined with a good level of horticultural, ecological and cultural knowledge. It includes two major traditions: formal rectilinear planting design (Persia and Europe); and formal asymmetrical (Asia) and naturalistic planting design. History Persian gardens are credited with originating aesthetic and diverse planting design. A correct Persian garden will be divided into four sectors with water being very important for both irrigation and aesthetics. The four sectors symbolize the Zoroastrian elements of sky, earth, water and plants. Planting in ancient and Medieval European gardens was often a mix of herbs for medicinal use, vegetables for consumption, and flowers for decoration. Purely aesthetic planting layouts developed after the Medieval period in Renaissance gardens, as are shown in late-Renaissance paintings and plans. The designs of the Italian Renaissance garden were geometrical and plants were used to form spaces and patterns. The gardens of the French Renaissance and Baroque jardin à la française era continued the formal garden planting aesthetic. In Asia the asymmetrical traditions of planting design in Chinese gardens and Japanese gardens originated in the Jin dynasty (266–420) of China. The gardens' plantings have a controlled but naturalistic aesthetic. In Europe the arrangement of plants in informal groups developed as part of the English Landscape Garden style, and subsequently the French landscape garden, and was strongly influenced by the picturesque art movement. Application A planting plan gives specific instructions, often for a contractor about how the soil is to be prepared, what species are to be planted,