Abstract: A horticulture growing medium mixture or so-called “potting soil” provides a generally soil-less medium that does not rely on the use of peat moss, soil or compost. A unique combination of anaerobically digested solids, perlite, vermiculite, and various additives and amendments provides a growing medium with a surprisingly high acid-buffering coefficient. Although the growing medium is particularly suited for orchids, the medium can be tailor-mixed for various other plants as well.