Hydrangeas add stature to your garden
Published 6:44 pm Monday, November 24, 2008
By Linda Stephens-Urbaniak
On Gardening
Hydrangeas have been dazzlers in American gardens for more than 100 years. They add stature to gardens with their deciduous or semi-deciduous leafy bushes, as well as interest while in bloom and later when the flowers dry on the shrubs. While big blue balls may come to mind, the latest interest is for the lace-cap, vining and other varieties.
With many, the flowers are influenced by the acidity of the soil; bluer with acid soil, the natural condition here in the Pacific Northwest. Pink is the standard with alkaline soil and can sometimes be achieved by adding two cups of dolomite lime each year and working it into the soil surrounding those plants that respond to color regulation. There are several cultivars that are stable in their color and are unaffected by soil pH.
These shade lovers can grow in full sun here in Cascadia if given ample water to keep their leaves from burning. But gardeners should conserve water by planting under more shaded conditions. Hydrangeas are easy to grow in rich, humus-laden soil. If planted in clay, add compost or composted steer manure. New plants can be propagated from cuttings taken in June or early July.
The old-fashioned hortensia, or mophead hydrangea, H. macrophylla, grows to about 6 feet and comes with the familiar rounded heads of florets. These shrubs boast large leaves. A similar looking blossom is produced on the PeeGee, H. paniculata grandiflora, which is covered with huge white flower clusters late in the summer. This is one plant that can really put on the growth, to 25 feet under ideal conditions. There also is a shorter form called `Pee Wee.’ Hydrangea macrophylla `Tricolor’ has dark green leaves strongly marked with cream and chartreuse and it will light up a dull, shaded area. The lacy ring of large light blue sterile flowers surrounds the small blue fertile florets, called a lace-cap. The display blends well with the variegation of the leaves. Other varieties of lace-caps can be found with white, pink, violet or blue floral displays, sometimes with contrasting sterile florets and fertile flowers.
Oak-leaf hydrangea, H. quercifolia, has elongated cream-colored flower clusters and some varieties even have a lovely scent. The large, to 12-inch, leaves emerge touched with burgundy before maturing to an even dark green during the summer, and then are touched with color in the fall. This plant is typically taller than it is wide and can add needed height to a perennial border.
There is even a climbing hydrangea, H. anomala petiolaris, that clings to trees, fences or walls with tiny rootlets and rarely needs pruning. A very similar plant, Schizophragma hydrangeoides (it has no common name), is also a climber but blooms somewhat later. Both form a lace-cap type flower and bloom in white.
As soon as the bush hydrangeas have finished blooming and the heads are starting to dry, they need to be pruned. Three years or so after planting, and yearly thereafter, take about one-third of the oldest shoots completely down to the ground. The rest of the bush can be lightly pruned to make an attractive display. Most hydrangeas bloom only on old wood, so just remove the spent flowers. This is one plant that shouldn’t be hard pruned in the spring if you want flowers during the summer.
There are new species with felted leaves, with strong vertical growth, with diverse leaf color and some that look like small trees. The breeders are at work and there will soon be many more types available. A shady spot in your garden can now hold a shrub that is similar to, but better than, those your grandmother was delighted to have in her garden.
Contact Linda at lindagardenlady@aol.com. She welcomes questions and will respond to as many as possible.
