Charlie Dimmock and the Rich brothers compete to design a contemporary garden with a nod to Zimbabwe. Grace lives with her mum Agnes in a new-build in Wantage. They have no idea what to do with the garden, but they want it to be more interesting than the empty plot it currently is. Having grown up in Zimbabwe, Grace would like to see a nod to that in the design, with exotic planting and a Victoria Falls-inspired water feature. With a budget of £3,500, which designer will win this ambitious project?