Landscape plantings, especially in urban situations, often requires different growing media to improve soil physical and chemical qualities or to use them as surrogate soil. A wide selection of materials, organic and inorganic, natural and synthetic, are available. Whether used alone or as amendments in a soil mix, a good understanding of their edaphic properties can provide an objective basis to make recommendations on the types and quantities to be adopted. The lack of relevant published information, however, restricts their rational use. This study evaluates 25 samples obtainable commercially in Hong Kong with reference to 17 edaphic attributes, and interprets the results mainly with reference to tropical horticulture. Copyright © 1996 by Marcel Dekker, Inc.