Hydrangea shrubs’ popularity has grown in the last decade, but especially in the previous 5 years, making them one of, if not the, most popular flowering shrubs. Gardeners around the world are attracted to hydrangeas because of their large, showy blooms, versatility, and how easy they are to grow. Other types of popular flowering shrubs include rose bushes, lilac shrubs, rhododendron shrubs, and azalea shrubs.