Shrub roses encompass a wide range of rose types which makes them a very diverse group. It seems that any rose that does not fit another category becomes a shrub rose and in turn their winter hardiness varies. Many shrub roses result from crossing old-rose types with modern roses and therefore combine the best traits of each: repeat flowering rose bushes and a great range of colors from the Modern Roses, and the fragrance, wide range of flower styles, growth habits, and also the delicate color from the Old Garden Roses. There are some very useful roses in this 'Shrub Roses' group. Many Shrub Roses are good for screens, hedges, and mass planting. Shrub Roses also make great single specimen plantings. Virtually all shrub rose bushes are repeat blooming. Hardy zones 5 to 10 with some hardier, and some less hardy.