Hooray for hydrangeas! Plants no longer overlooked
Native to North America and Asia, hydrangeas are opposite leaved shrubs with small individual flowers borne in large cluster of varying sizes. If you look closely at a hydrangea flower cluster, you'll likely notice two distinct types of flowers. The large, showy ones are sterile while the smaller, less conspicuous ones are fertile and can produce seed.
As you may imagine, plants are bred to produce these larger clusters of sterile flowers for a more spectacular show.
Older yards often sport specimens of the panicled hydrangea (H. paniculata, 'Grandiflora') commonly referred to as PG or PeeGee because of its Latin name. Astoundingly large, creamy white blooms are produced in late summer when most other trees and shrubs are cloaked in green. This variety is perhaps one of the hardiest and matures at 15 to 25 feet.
Although some find it distracting, I rather like the large flower heads slowly turning from cream to pinkish to a soft tan, providing visual interest throughout the winter. My favorite new panicled hydrangea is 'Limelight' with soft, pale green flowers that also take on a pinkish color with age. This one only grows to 8 feet tall or so and is easier to work into the shrub border.
The smallest panicled hydrangea that I am aware of is 'Little Lamb', a white-flowering shrub which reaches 4 to 6 feet tall, but may spread up to 8 feet across so give it some room for best show.
Another familiar hydrangea species is the smooth hydrangea (H. arborescens). It's also very hardy and forms a rounded bush with huge, creamy white flowers. It too is a later bloomer, flowering in July through early September. If left unattended, plants can attain a height of 8 or 9 feet, but if cut to the ground each spring, they will grow to a manageable 4 to 6 feet.
Like the panicled hydrangea, flower buds are borne on the current season's wood, so early spring pruning is fine. 'Annabelle' has been around for quite some time, but she does tend to flop over, especially when subjected to late summer downpours. Newer 'White Dome' may be just the replacement you're looking for, as flowers stay upright regardless of weather conditions.
Perhaps the best known and most sought after member of the hydrangea family is the bigleaf hydrangea (H. macrophylla). This is the large leaved, mophead hydrangea often sold by florists with huge clusters of blue or pink flowers.
Some older and florist varieties are not reliably hardy here, and while the plants may sprout leaves each spring, the flower buds which are formed in the fall are killed over the winter. If you didn't happen to live where the winters were on the mild side or situate your plant in a sheltered site, you often did not get those incredible blue flowers. Plant breeders have come to the rescue and now we can all have those heavenly blues.
It started with 'Endless Summer', a clear sky blue that blooms on new wood and well as old wood. Even if last fall's buds were killed by a hard winter, new flowers will form on this summers growth.
There are several other new hydrangeas that bloom on new wood that are definitely worth adding to your plantings, including an absolutely delightful one called 'Forever & Ever Double Pink'.
Many of you are aware the soil pH determines whether the flowers will be blue or pink. Actually the pH affects how soluble certain elements in the soil are. Two elements in particular, aluminum and iron, are responsible for the color of hydrangea blossoms with both of these elements becoming more soluble, thus available for plant uptake, in acidic soils.
Soils with a low pH and greater iron and aluminum will produce plants with bluer flowers, while those with a high pH result in pink ones.
In general, hydrangeas prefer a rich, well-drained but moist soil. The name hydrangea comes from the Greek 'hydro' meaning water, and 'angion' meaning bowl or tub. If adequate moisture is available, they will grow well in full sun. A mulch will help conserve moisture.
Bothered by few pests or diseases, hydrangeas may by just what your landscape needs for late summer color.
If you have questions about growing hydrangeas or on any other home or garden topic, call the UCONN Home & Garden Education Center, toll-free, at (877) 486-6271, visit www.ladybug.uconn.edu or contact your local Cooperative Extension Center .