| |
NEW 'ENDLESS SUMMER' HYDRANGEA A BLOOMING SUPERSTAR
Does the phrase "One of the most-significant new shrub introductions of the past 25 years" grab your attention?
How about "eight-inch diameter clusters of vibrant pink blooms that are nicely spaced throughout dense green foliage?"
How about "the plant performs well in full sun to dappled shade?"
These glowing words, from syndicated gardening columnist Don Engebretson, describe a just-released variety of hydrangea called "Endless Summer."
A major national release of the flowering shrub is scheduled for 2004. Botanically, the new shrub is named Hydrangea macrophylla 'Endless Summer.' For Minnesota gardeners, what is most exciting is that Endless Summer is reliably winter hardy and promises to bloom following -25 to -30-degree winters.
There are four main types of hydrangeas grown in Minnesota:
Hydrangea anomala (Common name: climbing or vining hydrangea; varieties: petiolaris)
Hydrangea paniculata (Common name: pannicle hydrangea; varieties: Pee Gee, Tardiva, Brussels Lace)
Hydrangea arborescens (Common name: smooth hydrangea; varieties: Annabelle, Grandiflora)
Hydrangea macrophylla (Common name: bigleaf hydrangea; varieties: Nikko Blue, Blue Billows, Endless Summer)
One way to categorize hydrangeas is by whether they form their buds and bloom in the same growing season ("on new wood"), or bloom from buds formed the previous growing season ("on old wood"). Most hydrangea varieties that bloom on old wood (H. anomala and H. macrophylla) fail to perform consistently in Minnesota because their flower buds are damaged by severe cold of Minnesota winters.
Engebretson uncovered an interesting story behind the introduction of Endless Summer. Two decades ago a man named Vern Black observed a bigleaf hydrangea blooming in his neighbor's yard that had survived the extreme-cold Minnesota winter of 1982. As superintendent for growing and propagation for Bailey Nurseries in St. Paul, Black realized this was an unusual plant. He took cuttings of his neighbor's plant and began the methodical process of propagation, testing and evaluating that led to the commercial production and initial introduction in 2003 of Endless Summer.
From the start, Engebretson explains, the new, unnamed variety of H. macrophylla was a blooming superstar in Bailey Nursery test gardens. They soon understood why: The plant had the capability to bloom from both old and new wood. It didn't matter if the flower buds survived winter or not; spring growth produced buds that bloomed later that same season.
Then, Engebretson explains, a second genetic twist appeared: Instead of one blush of bloom, the plant continued setting new buds, about every six weeks, into late summer. Genetic makeup of the mutant plant's offspring contained botany's Holy Grail: continuous bloom. There was also no denying that the plant had jumped a notch on the hardiness scale as well, with field specimens maturing over the years to five-feet tall and wide, suffering little winter die back.
While smooth and panicle hydrangeas are hardy and easy to grow, explains Nancy Rose, a University of Minnesota horticulturist, they don't have one feature that some gardeners desperately desire in a hydrangea: blue flowers. Blooms in that elusive celestial color (as well as shades of purple, pink and red) are found among the many cultivars of bigleaf hydrangea. These cultivars have either lacy, domed flowers or puffy, rounded "mophead" flowers. Bigleaf hydrangeas prefer moist, acidic soil. In fact, the acidity of the soil can change the flower color, from blues in very acidic soil to pink in neutral or alkaline soils.
Engebretson says that, in acidic soils (pH 5.5 or lower), the bloom color of Endless Summer is a clear, sky-blue. If your soil is alkaline (as are most soils in the Twin Cities and much of greater Minnesota) and you don't want to monkey around acidifying it, the flowers will open a lovely clear pink.
Michael A. Dirr, author of the 1,010-page Manual of Woody Landscape Plants, writes that during his career, he has tracked Hydrangea species with the fervor of a horticultural Dick Tracy. "I've had a great time postulating that continuous flowering Hydrangea macrophylla cultivars might be discovered or bred. Events of the last three years substantiate that reality. Could it be so...Hydrangea macrophylla flowering in Caribou, Maine, and International Falls, Minnesota? I must be dreaming!"
|
|
|
 |
| |
|
 |
| |
PUTTING DOWN ROOTS:
A Delightful Blend of
Gardening Wisdom, Wit
and Whimsy
$10 + $2 for shipping
by Cliff Johnson |
 |
 |
| |
|
