Abstract: Plant growth media are described as composed of various combinations of vermiculite, perlite, and clay and having superior properties for use as potting soil for container-grown plants. Such media are characterized by greater moisture capillarity and available moisture retention. There is also less danger of plant injury through nutrient deficiencies, over-fertilization, of pH changes. Such media are also characterized by their dry state physical properties in the form of non-compacting, light weight, non-vitreous, rigid foam structures. The dry state media have plant nutrients uniformly distributed throughout and fixed in place. These properties make the media superior for wet-casting into plant containers or extruding into pellets. After filling and upon drying, the media-containers can be inverted without dislodging their contents and the media can be repeatedly wetted and dried while maintaining the desired foam structure.