Yellow Wave' New Zealand Flax (Phormium tenax 'Yellow Wave') The sword-shaped leaves of New Zealand flax create a lush look but require virtually no care, so the Ocampos used several varieties of it in the front bed, the side yard and the back. It's hardy to 20 degrees F. New Zealand hook sedge (Uncinia rubra) is a somewhat hardier substitute that is cold-tolerant to 10 degrees F.
This is the Outer Space section of Woodend Primary School's (South Australia) Stephanie Alexander Kitchen Garden. The photo shows the garden in 2011 and in 2013 - it is starting to look like a forest from outer space. :)