Home › Words › H › hydromulchinghydromulchinghydromulching · noun — A form of mulching in which the mulch is combined with water and a tackifier and then sprayed.Definition from Wiktionary (CC BY-SA 3.0).EtymologyFrom hydro- + mulching.nounA form of mulching in which the mulch is combined with water and a tackifier and then sprayed.Definitions & examples from Wiktionary (CC BY-SA 3.0).