The environmental droid, informally known as a gardener droid, gardening droid, or landscaping droid, was one of the five major subcategories of second-degree droid, along with astromech droids, engineering droids, exploration droids, and sophisticated repair droids. Environmental droids were used to trim gardens, prune hedges, and to perform other tasks to improve the appearance of an area of land. Different models were fitted with a variety of tools, such as shears or watering implements. Around 32 BBY, the Mark II Z3-NO line landscaping droid was popular among the rich citizens of the galaxy. Gardener droids were used aboard the luxury liner Star of Empire during the Galactic Civil War. In 40 ABY, a gardener droid found Jedi Master Tresina Lobi's body in the hedges of Fellowship Plaza, after she was murdered by Lumiya and Alema Rar in a Duel in the Fellowship Plaza.