In addition to considering the pavement materials on a site, the landscape designer must also determine the materials and patterns of walls, fences, benches, trellises, overhead structures, and so on. The following paragraphs outline a palette of common materials used on the residential site for these structures. As can be seen, many of these materials are similar to those used on the ground plane, although their composition and patterns are often different when applied to site structures.
As with pavement, there are many types and shapes of stone that are available for use in landscape structures. The most common types fall in three broad categories: boulders, slabs, and cut stone.
Boulders Boulders are a generally rounded stone that is found unquarried along water bodies or in regions of rocky terrain (Figure 12—60). Boulders commonly range
Material patterns can be coordinated with significant historical patterns of an adjoining house.
in size from 3 to 12 inches and are gray, tan, and buff in color, although they may be found in other colors depending on the region and their geological source. Boulders can be used to:
• construct retaining walls and free standing walls if they are mortared in place (Figure 12-61).
• provide a rustic character appropriate for sites near water or rural sites surrounded by a native landscape.
• create a distinct rounded surface texture.
• furnish accents within planting areas.
Slabs Slabs are large dimensional stones that are quarried and cut, but often retain a rough, irregular character. Slabs vary widely in size from 6 to 12 inches in height and 2 to 4 feet in depth and length, although larger sizes are available. The color of stone slabs depends on their geological source, with many being gray, buff, or light yellow in color. Streaks of yellow, orange, or blue tones are common in some slabs. Slabs are appropriately used on the residential landscape to:
• create low retaining walls that have a hefty, solid appearance.
• replicate rock outcrops when they are set into a slope in a stepped fashion (Figure 12-62).
• create rugged steps.
Cut Stone Cut stone is stone that is quarried and cut into relatively flat units. The exact quality of cut stone varies widely depending on the geological source and the degree of precision in cutting. Some cut stone retains a rough, tumbled appearance, whereas other cut stone has very clean and straight edges (Figure 12-63). The size of cut stone generally ranges from about 1 to 6 inches in height and 1 to 2 feet in length. Cut stone can be used to:
• create either mortared or dry-laid stone retaining walls, many with a distinct horizontal character.
• construct free-standing walls.
• establish either a rough, irregular visual character or a refined, elegant quality depending on the exact type of cut stone selected.
• define any plan form including curves and arcs (Figure 12—64).
• visually associate a stone house with the landscape.