Maybe you've never heard of a mountain hydrangea (H. serrata), but you've almost certainly seen one. They are closely related to bigleaf hydrangeas, but originate in the chilly mountainous regions of Japan. This has resulted in mountain hydrangeas naturally developing better bud hardiness than bigleafs, but with the same lush color and abundant flower coverage. If you've struggled to grow the big blue, purple, or pink hydrangeas you've dreamed of, a mountain hydrangea may be just the plant to make that a reality!