The artist as gardener idea has been recently clarified by Brian Eno in this short talk at Serpentine Gallery.
The concept is a basic difference in the way we see the world. Brought up on the idea of a supreme creator with intelligent design it is difficult to accept the idea of evolution. A simple origin for a complex system is not an obvious transition.
The idea of the hero artist/architect creating fully realized complex masterpieces is one we accept easily elevating the artist to the realm of a god.
The concept of free will allows for us to work within a system in collaboration guiding and riding as the moment dictates. In art this is process oriented work as opposed to product oriented. Eastern philosophy has opened the western mind to notions of staying in the moment and mindful enterprise which dovetails nicely with this view of the artist as gardener rather than architect. Rather than start off with a fully realized plan he enters in to a process of discovery remaining open to shifts and pressures.
Mr Eno wants to experience the work as it develops with the audience and to that end he creates systems of simplicity which generate complexity.
This is the theory behind Field of Voices and the upcoming Field of View. We have created a system to be populated by contributors with very little guidance and a lot of anticipation. We are as surprised as anyone by the result and the hero artist is us all.