Designed by award-winning firms Gustafson Porter and Gustafson Guthrie Nichol, the installation - Towards Paradise - has been created in the overgrown grounds of the former Church of the Virgins.
The garden is composed of three main spaces linked by pathways, which tell a story of past, present and future.
"Remember" symbolises memories of what has been lost, while in "Nourishment" there is sustenance for body and soul. A clearing leads to "Enlightenment", where a sculpted landform offers space for reflection.
Gustafson Porter director Neil Porter said: "We believe landscape architecture is a greatly neglected subject, so we are hugely excited by the opportunity of engaging with visitors at the Biennale."
As part of the Venice Biennale, which dates from 1895, an international architecture exhibition - Out There: Architecture Beyond Building - is taking place from 14 September to 23 November.