Answer: A few of the hardiest perennials for Colorado include:
Penstemons: Rocky Mountain (Penstemon strictus) and Scarlet bugler or iron maiden (Penstemon barbartus); Hollyhock, Alcea Rosea, easy from seed and often self-seeds;
Purple Coneflower, Echinacea purpurea, a native of the tallgrass prairie, large clumps can be divided; Lupine hybrids, Lupinus; Black-eyed Susan or Gloriosa daisy; Mexican hat coneflower: Ratibida columnifera.
Best wishes with your garden!
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