Silver thiosulfate

Silver thiosulfate (STS, chemical formula Ag2S2O3) is an inorganic chemical that can promote early flower growth and promote flower duration in a variety of plants.

An aqueous solution of silver thiosulfate can be prepared by mixing solutions of sodium thiosulfate and silver nitrate. When used for plant assays, it is prepared using excess thiosulfate, giving the [Ag(S2O3)2]3– complex ion.