large-sized foliage shrub specie form very slowly maturing at 15' tall by 15' wide cultivars are smaller (10' by 10', or less, making them medium-sized shrubs), and often are kept to an even smaller size by shearing, irrespective of their specific genetic potential for size upright vased growth habit in youth, becoming spreading rounded and horizontally layered with age (if rarely or never pruned) slow growth rate