Greaseberry plants grow in the Gorgs' Garden. The leaves of the greaseberry plant are harvested (when in season) by the Fraggles and used for sliding across the Great Hall. Some Fraggles have attempted what is known as "The Ultimate Slide". The leaves are also used to play the sport of rock hockey.
The seeds of a greaseberry make soup taste awful to the Gorgs. Pa is the only Gorg to enjoy such soup's flavor. This information was put to good use in one episode when Marjory was frozen over. In order to thaw her out, Gobo and Mokey added greaseberry seeds to the Gorgs' goombah soup. This made the soup inedible, according to Ma, and it was thrown into the Trash Heap.