Every gardener seems to have memories of a hydrangea somewhere in the garden, said a University of Illinois Extension horticulture educator.
"These old fashioned plants have been a part of gardens dating back to the early 1800's when Pee Gee hydrangea was a garden staple," said Greg Stack. "With white flowers and a tall, floppy habit and not always looking their best, they seemed to be the shrub of choice to fill up a corner or add to the foundation planting.
"But what has happened to the garden hydrangea may surprise you. Plant breeders have been at work to improve the quality of the plant with flowers that are literally huge and in colors no one could have imagined back in the 1800's."
These shrubs are a sought after addition to the summer garden providing a large splash of color when few other shrubs are in flower. They also can add much needed interest to the winter landscape with their large, papery brown flower heads.
"And when harvested at the proper time and dried, they can add quite a bit of interest and excitement to indoor arrangements," he added.
With hydrangeas as other plants, one size does not fit all. When shopping for hydrangeas it's good to look closely at the botanical name of the plant on the tag. This can offer help in determining the plant's ability to provide flowers even after severe cold or improper pruning.
Hydrangea arborescens types set flower buds on new stems as do Hydrangea paniculata. What this means is, these can be cut back severely in the spring to maintain size and they will still provide flowers. Also, if there is an exceptionally hard winter and the stems are killed back to the ground, the new stems produced will be able to set flower buds.
Hydrangea macrophylla types, often called lace cap hydrangea have flower heads composed of tiny disk shaped fertile flowers in the center surrounded by much larger sterile male flowers in the outer ring. This creates quite a different look out in the garden.
"These hydrangeas were often difficult to get to re-bloom in cold climates because they produced flower buds on last year's stems or the old stems," he said. "If they experienced severe winter injury and were killed to the ground, the new stems produced during the season were unable to produce flowers. That has since changed with new introductions of macrophylla types that bloom on both old and new stems. This now gives gardeners a chance of bloom even if stems get killed to the ground."
One of the most adaptable and urban tolerant hydrangeas are the Hydrangea paniculata types. These plants prefer a well prepared, moist soil in either full sun or partial shade.
Within the paniculata types some that would make good garden additions include:
'Fire and Ice' is a large shrub growing to six to10 feet tall with attractive green/red foliage. Flowers start out creamy white in early summer, turn dark pink in midsummer and then a very deep red in autumn.
'Bombshell' is a hydrangea with a dwarf habit growing to only two to three feet tall. There is a large abundance of white flowers produced from early summer through fall. This is a nice compact plant for the small space garden.
'Quick Fire' blooms early with dense pyramid shaped flower heads going from creamy white to vivid dark pink as the summer progresses. 'Quick Fire' grows six to eight feet tall with rosy red stems.
'Limelight' is a plant that offers something a bit different. While growing six to eight feet tall it produces lime green flowers that mature to white and the eventually take on a burgundy hue in the fall.
Hydrangea arborescens types are also good garden hydrangeas.
"They do best when grown in a rich soil that is well drained yet retains some moisture," said Stack. "They prefer part shade but will grow in full sun if given ample moisture. Here are some to consider for your garden."
'Invincibelle Spirit' is the first pink flowering 'Annabelle' hydrangea. This plant produces loads of hot pink flowers from summer to fall and the color is not affected by the pH of the soil. It grows to about four to five feet.
'Incrediball' is and improved version of an old reliable, 'Annabelle.' As its name implies the flowers are very large, up to 12 inches in diameter. In addition the stems are much sturdier than 'Annabelle' and are able to hold the large flower heads up and keep them from flopping. 'Incrediball' grows to four to five feet.
'Grandiflora' has flowers similar to 'Annabelle' only smaller. Green buds open to white and they back to green. This hydrangea grows to four to five feet tall and is excellent for the shady shrub border.
"In the Hydrangea macrophylla class, some dependable shrubs to look for that bloom on both old and new stems include some of these introductions," he said.
'Blushing Bride' grows to two to three feet tall and produces six-inch blooms that start out pure white and then mature to a soft pink. This plant needs a moist soil to do best and will grow in part to full shade.
Source: Greg Stack, Extension Horticulturist, firstname.lastname@example.org
Pull date: May 31, 2011