Kay Lancaster wrote :

On Tue, 07 Aug 2012 07:57:58 -0700, David E. Ross
wrote:
I always thought of impatiens and coleus as annuals. However, Sunset's
"Western Garden Book" describes coleus hybrids and Impatiens walleriana
(busy Lizzie) as perennials.

Many "garden annuals" are annual only because a heavy enough freeze
comes along. Keep 'em from freezing and you can keep them growing for
many years.

Did I menion being in the Denver area?

No, I want something that's a true perennial, down to zone 4, please.