Shrub roses, like groundcovers, show excellent disease resistance, are low maintenance and have remarkable blooming capacity. They are considered to be the best "non-rose grower's rose". Because of their attributes, shrub roses have become some of the most popular types. Most are crosses between classic modern roses and old-fashion types. Flower shapes and structures are quite variable, some are fragrant, in a wide array of colors, and plants grow to a modest size of only 2 to 5 ft.