Karl Foord and Kathy Zuzek, UMN Extension Educators
I photographed the rose collection at the Arboretum last week and tried to make sense of the many rose classifications and the varieties within each classification. Twenty three classes are evaluated in the publication Roses for the North(1). The British Association of Rose Breeders (BARB) has identified 30 rose classes, and the American Rose Society has identified 56. Regardless of which system you choose, the situation is complicated. Being faced with this situation, I consulted our rose expert Kathy Zuzek, who is the lead author of the Roses for the North publication. We decided to address the issue with two articles. The first would suggest the best rose cultivars for Minnesota based on Kathy's twenty plus years of experience. The second would be an historical article describing why there are so many categories, what each looks like, and how that category performs in Minnesota. The second article will appear in the July 15 edition of the Yard & Garden News.
The choice of best rose cultivars for Minnesota is based on three criteria, cold hardiness, tolerance to black spot disease, and repeat blooming. Simply put, the rose has to tolerate Minnesota winters through a minimum of cane die back and good regrowth vigor in the spring. The plant must tolerate black spot and not defoliate in July from pressure due to this fungal disease. The plant should produce a good flower show throughout the season.
Fourteen varieties met the criteria mentioned above. Twelve of the varieties are pictured below; varieties Cuthbert Grant and Topaz Jewel were selected but are not pictured below. Consult Roses of the North for more complete descriptions of the selected varieties.
Photo credits: Karl Foord
1. K. Zuzek, M. Richards, S. McNamara, and H. Pellett. Roses for the North - Performance of Shrub and Old Garden Roses at the Minnesota Landscape Arboretum. Minnesota Agricultural Experiment Station University of Minnesota, Minnesota Report 237-1995. 1995.