The Hydrangea brightens the landscape like no other shrub. Its large blooms of white, pink, blue, or even lavender are striking in shaded areas. There are five main types of hydrangeas: Hydrangea aborescence or smooth hydrangea, Hydrangea quercifolia (oakleaf hydrangea), Hydrangea macrophylla (bigleaf hydrangea and lacecap hydrangea), Hydrangea paniculata (panicle or Pee Gee hydrangea) and Hydrangea anomala (climbing hydrangea).
One of the hardiest hydrangeas is the smooth hydrangea like “Annabelle” or “Grandiflora”. It’s frost hardy, can withstand long periods of hot dry summer without watering and can be cut to the ground in late fall or early spring. “Annabelle” grows only 3-5 feet tall and has the most spectacular globes of white blooms from June to September. Sometimes after a heavy rain, the big white globes droop. The shrubs can be supported by planting several shrubs close together, so that they support each other or by encircling the shrubs with low wire fencing early in spring before the plants leaf out. Like all hydrangeas, “Annabelle” is relatively disease and pest resistant.
Another one of my favorites is the beautiful and hardy oakleaf hydrangea. It is a native plant and does well in a wooded setting or as an understory shrub. Oakleaf hydrangeas have large deeply lobed oak-like leaves and conical heads of white florets, 4-12 inches long, from July to September. The large leaves turn a deep red in fall and the older stems exfoliate to a rich cinnamon brown bark. Oakleaf hydrangeas are not as readily available at some local garden centers and you may have to order one from a garden catalog. “Snow Queen” and “Alice” cultivars grow 6-12 feet tall. There are dwarf oakleaf hydrangeas that grow only to about 4 feet. Flowering occurs on wood produced the previous year, so prune only right after flowering. In contrast to pruning of Hydrangea aborescence, pruning should be minimal.
The most popular hydrangea is Hydrangea macrophylla. This group includes the mophead and lacecap hydrangeas. The mophead hydrangeas are covered with large balls of pink or blue flowers, pink in alkaline soil and blue in acidic soil. The pink color can be obtained by adding lime. It grows 3-6 feet high and makes a great foundation plant. Unlike Hydrangea aborescence and similar to oakleaf hydrangeas, it blooms on old wood, meaning that flower buds for the next year are formed on the previous year wood. Some of the new cultivars like “Endless Summer” are more cold hardy and bloom on both “old wood” and new shoots. Although beautiful, mopheads and lacecaps are less hardy than Hydrangea aborescence and require more moisture during the summer. Sometimes mopheads and lacecaps don’t bloom. The main reason for not blooming is that the buds, which were formed the year before, were killed off by frost or they were pruned off by mistake. It is best not to prune Hydrangea macrophylla unless you know some branches are dead or the shrub needs thinning, which you can determine in spring when the leaves form.
Panicle hydrangeas are the most cold-hardy hydrangeas. White flowers appear in mid-summer on 6-8 inch panicles. Unlike other hydrangeas, which need some shade; this type does well even in full sun, as long as the ground remains moist. Panicle hydrangea can be grown as a shrub or small tree, reaching a height of 10-20 feet. It can be pruned at any time, because it blooms on new wood only.
Climbing hydrangeas is a clinging vine with white flowers and can grow up to 60-80 feet long. The vine can become heavy and will need strong support. Very little pruning is necessary. Prune side shoots, once the hydrangea is well established.
If you want stunning blooms all summer long and carefree shrubs, plant some hydrangeas. The flowers also make beautiful dried flower bouquets for indoors. The dried flowers do best when allowed to dry on the plant before picking.