A 955sq m section will be sown and planted with 100 species to transform it into a sustainable, non-irrigated plot using the latest ecological-horticultural research. The first flowers are expected to appear in summer 2012.
The scheme was designed by Sheffield University horticultural ecology professor James Hitchmough, who contributed to the meadows at the London 2012 Olympics Park and a prairie next to RHS Wisley's millennium glasshouse.
He is particularly interested in seed because it "allows you to establish complex plant communities, letting natural selection do the rest".
The Oxford border was inspired by the herbaceous plants and grasses of three seasonally dry regions not widely grown in public gardens in Britain but that will become increasingly important if current climate change predictions are accurate.
The border has alternating triangular wedges of different plant communities with an overlay of tall seasonal emergents such as Eremerus, Kniphofia triangularis and Silphium. Although designed to be colourful, it also has a strong architectural structure, with tall see-through stems and mega herbs punctuating the ground layer.
Gardens curator Tom Price said: "The border will be an exciting example of sustainable horticulture and communicate the importance of minimising the impact on the environment."