ABSTRACT
This chapter examines two essentials of plant assemblages: the nature of the vertical layering typical of natural plant communities, and how this can provide a model for design. The herb layer in podocarp-broadleaved forest is dominated by ferns and sedges but does include some other flowering plants. The first is the groundcover principle: that complete cover of the ground area at one or more levels is a sign of a well-developed plant community growing under favourable conditions. The ornamental equivalent of this is a common planting idiom in large-scale public and corporate landscape. Shrub- and field-layer combinations are a common planting approach in ornamental areas of parks, gardens and courtyards, in planting close to buildings and where overhead or underground services preclude tall growing or deep rooting trees. The plants that comprise this layer can be of various forms from tussock grasses to hummock and mounded plants that spread through the spaces between the grasses and taller emergents.
