Berkheya purpurea, South African Thistle

Large, smoky-purple, daisy-like flowers bloom in summer on 3–4 ft tall spiny stems. They are so unusual that they usually require a double take from uninitiates. And...drum roll...they are one of the few deer-proof (as opposed to deer-resistant) plants. Not even young deer are so bold as to sample them. Keep in mind that they send down a tap root that insists upon staying put and not being moved about willy-nilly. South African. Particularly long-lived perennials, we have had one in the same spot for 15 years and counting.   Minimum temperature: 0° F