Posted by Aaron Barton on Jun 18th 2021
With their showstopping blooms and classic shape, hydrangeas are a timeless staple fit for any garden, shining as specimen plants or beautiful flowering hedges when massed in both formal and informal garden designs. Native to China, Korea, Japan, as well as North America, Hydrangea are commonly available in cultivars of three species—the bigleaf hydrangea, Hydrangea macrophylla, the panicle or hardy hydrangea, Hydrangea paniculata, and the smooth hydrangea, Hydrangea arborescens.
Hydrangea macrophylla (hy-DRAIN-juh mak-roh-FIL-uh) are part-shade, compact hydrangeas that bloom colorful spherical flower clusters in many vibrant colors, including varieties whose flower color changes with soil pH. These varieties, such as the Endless Summer ‘Twist-n-Shout,’ will have blue flowers with more acidic soils treated with soil acidifier, and pink flowers with more basic soils treated with garden lime. Other, non-transforming color varieties include the purple and pink flowers of Seaside Serenade ‘Newport’ and the pink flowers of Seaside Serenade ‘Hamptons’. Modern bigleaf cultivars bloom on new and old wood (the current and previous season's growth) from early summer to fall, meaning pruning can be done at anytime, but is best performed in the spring after the first flush of blooms, if desired. As their name implies, bigleaf Hydrangea form attractive mounds of large green leaves, maturing to around three to four feet tall and wide.
Hydrangea paniculata (hy-DRAIN-juh pan-ick-yoo-LAY-tuh) are part to full sun, typically larger shrubs, ranging in size from three to eight feet tall and three to six feet wide, that bloom large, conical panicles of flowers on new growth from the early summer to fall, persisting for excellent dried winter interest. There are countless classic varieties of panicle Hydrangea to choose from, including the beautiful white flowers of the more compact ‘Bobo,’ the rosy light green flowers of ‘Limelight’ and the dwarf ‘Little Lime,’ as well as the striking earlier blooming pink flowers of ‘Quick Fire’ and the dwarf ‘Little Quick Fire.’ Prune panicle Hydrangea in the late winter or early spring before they leaf out, pruning back each stem by up to 30-50% in length to promote dense new growth and abundant blooms.
Hydrangea arborescens (hy-DRAIN-juh ar-bo-RES-senz) are part to full shade, moderately sized, North American native Hydrangea with large, spherical flowers that bloom on new growth. Smooth Hydrangea should be pruned back to one to two feet above ground in late winter or early spring to encourage vigorous spring growth and help prevent plant flopping. Iconic smooth Hydrangea varieties include the stunning white flowers of the classic ‘Anabelle’ and the sturdier, more upright ‘Incrediball,’ the green flowers of ‘Seaside Serenade Bar Harbor,’ and the mauve flowers of ‘Invincibelle Mini Mauvette.’
Additonally, Hydrangea anomola (hye-DRAYN-jee-uh an-NOM-al-a), the climbing Hydrangea vine, provides the stunning blooms of Hydrangea shrubs on an adaptable woody deciduous vine. Preferring full or part sun yet tolerating shade, climbing Hydrangea are excellent for covering walls, fences, and large arbors, reaching a mature size of upwards of six feet wide and 30+ feet tall. A rugged vine for a variety of conditions, climbing Hydrangea are also resistant to deer and rabbit feeding. If desired, prune climbing hydrangea back after blooming.