Sub-Zero Rose Care in Winter
Many of those selling the Brownell sub-zero roses for cold climates claim that they are hardy to zone 3, but they still require good winter protection. Sub-zero roses are typically hardy from -15 to -20 degrees Fahrenheit (-26 to-28 C.) without protection and -25 to -30 degrees Fahrenheit (-30 to -1 C.) with minimal to moderate protection. Thus, in zones 5 and below, these rose bushes will need winter protection.
These are indeed very hardy roses, as I have grown Nearly Wild and can attest to the hardiness. A cold climate rose bed, or any rose bed for that matter, with Brownell roses or some of the Buck roses mentioned earlier would not only be hardy, disease resistant and eye-catching roses, but offer historical significance as well.