There is a lot going for knockout roses–few diseases, vigorous, easy to grow, available everywhere, and several different colors. Yes, these shrub roses are the most popular type of roses that have been introduced in years. First, in terms of vigor, red is by far the most vigorous. While the pink grew well for me, the other colors were not as vigorous. So don’t judge all the colors by the size of the red ones. Speaking of size, I have seen masses of red knockouts up to six feet tall in full sun. In my garden, I kept mine pruned to control its size. While pruning is not necessary, like the famous hybrid tea roses, I think severe pruning every two to three years is a good idea. Now if you want the perfect rose for cutting, these are not for you. Like most shrub roses, they look better from a distance, and in mass, versus close-up. So remember, if you decide to add them to your landscape, give them a sunny, well-drained location in pretty good soil. In my opinion, some of the other shrub or carpet roses are better for most well-kept home landscapes. But for blooming, you cannot beat knockouts.