51 Hydrangea paniculataCommon Names: peegee hydrangea, panicle hydrangea Family: Hydrangeaceae (hydrangea Family)
Panicle hydrangea is a deciduous wide-spreading, rather rangy shrub or small tree with big showy pyramid-shaped clusters of white to pink flowers that literally weight down the branches. Peegee hydrangea starts branching near the ground and has a rounded shape, getting 10-25 ft (3.1-7.6 m) tall and just as wide, although many specimens stay considerably smaller. The leaves are opposite, oval, have pointed tips and toothed margins, and are 3-6 in (7.6-15.2 cm) long. The flowers are borne in erect panicles 3-10 in (7.l6-25.4 cm) tall.
[A panicle is a flower cluster in which the flowers are at the ends of branched stalks that come laterally off an elongated central shoot; the flowers mature from the bottom upward. Compare to a raceme in which the flower stalks are not branched and a spike in which the flowers don't have stalks at all.]
Panicle hydrangea blooms over a long season, with the flowers starting out white in mid-summer, aging to pink and finally turning rusty brown in autumn. Unlike bigleaf hydrangea (H. macrophylla), flower color does not vary with soil pH. Peegee hydrangea's dried flowers persist (although they are not at all attractive) even after the leaves have fallen. Panicle hydrangea and oakleaf hydrangea (H. quercifolia) from the southeastern U.S. are the only hydrangeas with cone-shaped flower clusters; all the others have their flowers in rounded or flat-topped clusters.
Peegee hydrangea (H. paniculata 'Grandiflora') is the most common cultivar, available by mail order and from garden centers throughout the northern U.S. Its huge flower clusters start out snow white, age to pinkish purple and can be as large as 18 in (45.7 cm) long and 10 in (25.4 cm) wide at their bases. It is sometimes pruned to a single leader to form a small tree and then called "tree hydrangea." 'Unique' also has large flower clusters but starts blooming earlier in the season. 'Tardiva' is a little less coarse in the landscape with smaller flower clusters (to 6" long) that bloom later in the season, usually not until well into autumn.
Hydrangea paniculata is originally from Japan and eastern China.
CulturePanicle hydrangea is a fast growing, adaptable shrub that thrives almost anywhere. It tolerates acidic to neutral soils as long as they are well drained. You can prune panicle hydrangea in late winter since it produces its flowers on new growth. To get the biggest flower clusters on your block, reduce the number of stems by cutting the previous year's shoots back to within just a few buds of the main branches. If you don't, you'll have smaller, but more numerous flower clusters. Light: Full sun to partial shade. Hydrangeas benefit from some shade in the middle of the afternoon, especially in hotter regions. Moisture: Peegee hydrangea requires moderate watering during the growing season. Hardiness: USDA Zones 3 - 8. Peegee hydrangea is the most cold hardy of the cultivated hydrangeas. Propagation: Hydrangeas are relatively easy to start from cuttings. Take fast growing green-wood tip cuttings in spring or summer and root in moist sand or potting medium. Most of the flowers on the cultivars and many on the species are sterile and do not produce seeds.
Panicle hydrangea is best suited to the far corners of a landscape or in mixed shrub borders where its coarse texture will not stand out. Many gardeners think this hydrangea is more attractive when pruned to tree form. With thoughtful pruning it can be an attractive specimen as a shrub or a tree.
Panicle hydrangea is the most cold-hardy, most adaptable, most tolerant of urban conditions, and the most commonly cultivated hydrangea in the northern U.S. Its pyramid shaped clusters of white to purplish-pink flowers have brightened American yards for almost 150 years. However, the plant has an overall coarse texture in all seasons and is difficult to use in most landscape settings. Many landscapers these days are bored with it and no longer recommend it (although it may be experiencing newfound popularity is some areas). Michael Dirr, the famous horticulturist from the University of Georgia and author of Dirr's Hardy Trees and Shrubs suggests planting it in the neighbor's yard.
Steve Christman 9/13/00; updated 2/12/04, 4/25/11, 8/27/12