In 1959 the Morden Agriculture Canada Research Station introduced ‘Prairie Dawn’, the first high quality, cold hardy (Zone 3) modern shrub rose developed in Canada. It has attractive, semi-double, salmon-pink flowers that repeat their bloom. Although the rose breeder at Modern at the time was H.F. (Bert) Harp, it was likely his predecessor William Godfrey who developed this cultivar. Godfrey had previously developed several Rosa spinisissima cultivars, including ‘Prairie Youth’, the pistillate parent of ‘Prairie Dawn’.
‘Prairie Dawn’ is unusual for a cold hardy cultivar because it has Hybrid Tea cultivars in its pedigree. Normally that would negate tolerance to very cold temperatures. However, both sides of the parents pedigree include Rosa spinosissima altaica and this probably accounts for the cultivar’s exceptional cold hardiness.
There isn’t much emphasis on increasing the cold hardiness in Hybrid Tea breeding programs. But for breeders having this goal, a shot of ‘Prairie Dawn’ might be valuable to use. Because this cultivar has Hybrid Tea cultivars in its pedigree, this can only be a good thing when crossing with Hybrid Teas to obtain good quality progeny.
‘Prairie Dawn’ is classified as a shub rose but in reality it is a Pillar rose that can reach 3 metres in cold (Zone 4) climates. In warmer climates, of course, it will grow taller and probably would be a Climber. Therefore, this cultivar would have potential to use in Climber rose breeding programs. I would be inclined to use it with Rosa kordesii Climber cultivars, especially the Explorers. Like the Explorer Rosa kordesii cultivars, ‘Prairie Dawn’ has essentially ‘New Dawn’ in its pedigree (the cultivar that sported to ‘New Dawn’). ‘New Dawn’, of course, has been one of the most valuable cultivars to use in breeding programs, so having it on both sides in the pedigree of rose cultivars crossed with each other can only be a positive move.
Finally, since the shrub characteristics are predominantly Rosa spinosissima this cultivar could produce some interesting Rosa spinosissima selections. Especially if it was combined with yellow cultivars. However, since ‘Prairie Dawn’ is not a good pistillate parent and yellow Rosa spinosissima cultivars are also not great pistillate parents, a fertile pistillate parent breeding line ideally should be developed. Perhaps it could be done by crossing Rosa spinosissima with cultivars like ‘Maigold’, Suzanne’ or J5. A long term project but the results could produce some exceptionally beautiful and fragrant cultivars.
I wonder why Dr. Griffith Buck didn’t use ‘Prairie Dawn’ in his breeding programs. To me, that would have been an ideal cultivar to use for the goals he had.