Northern climate dry landscaping - the pictures to prove it

So I was quite impressed when I got to my parents and saw that the little city they live in had gone for a zero water garden curb planting scheme with Euphorbia, acanthus Spinosa and some grasses mixed with centrathus. Here are the pictures to prove it. Will check it regularly and report on progress, especially in snowy weather. After all what is the hardiness in winter ?