Patent ID: 8486430

Claim:
A vegetation culture active agent delivery medium having an overall density and comprising: a plurality of mineral granules containing at least 30 percent by weight of a mineral, said mineral having a bulk density of greater than 70 pounds per cubic foot and a mean mineral granule size, each of said plurality of mineral granules comprises a plurality of mineral fragments and a binder joining said plurality of mineral fragments; a plurality of cellulosic granules having a bulk density of between 8 and 45 pounds per cubic foot and a mean cellulosic granule size; and a vegetation culture active agent in simultaneous contact with said plurality of mineral granules and said plurality of cellulosic granules, said active agent being present from 1×10 −5 to 10 total weight percent of the medium, wherein water absorption by said plurality of cellulosic granules facilitates prolonged wetting and dispersion of said plurality of mineral granules into said plurality of mineral fragments and the mean mineral granule size is larger than the mean cellulosic granule size.