Dragon dung or
dragon manure is used as a fertilizer (
GF5). It can be bought at an apothecary in
Knockturn Alley (
CS4).
Hagrid nearly knocks Harry into a barrel of dragon dung when he runs into him in Knockturn Alley (
CS4).
Fred and
George Weasley send
dragon dung to their brother
Percy when he starts working for the
Ministry of Magic in the summer of
1994. Percy claims that it was a fertilizer sample from
Norway, and therefore "nothing personal" (
GF5).
During a
Herbology class in
January 1996,
Susan Bones talks to Harry, sympathising with his position of unwanted fame due to the recent flight from
Azkaban of the
Death Eater who murdered
Edgar Bones, his wife and children. Susan is distracted, and dumps too much
dragon manure on her tray of
Screechsnap seedlings. This upsets the seedlings, which wriggle and squeak in irritation (
OP25).