September 10, 2011
HYDRANGEAS ARE ONE OF my favorite flowers. My husband refers to them as "grandmother plants." That seems like a pretty good description, as I can vividly recall giant blue, globe-shaped flowers on big leafy bushes in my grandmother's yard in Hickman, Ky., when I was a little girl.
Most of us are familiar with the old-fashioned perennial shrub, hydrangea macrophylla or bigleaf hydrangea, which we see growing in most parts of the United States. Locally, we find them in shades of pink, light blue, violet and purple. The color can vary even on an individual plant and is determined largely from the amount of aluminum available in the soil, soil acidity and also by the stage of floral development. Bigleaf hydrangeas should not be pruned in winter or early spring as they bloom on old growth. This creates a problem for areas with weeks of sub-zero temperatures where the plants freeze to the ground and their old growth ceases to exist.
The large, round hydrangea macrophylla is often referred to as a "mophead." Also in the macrophylla group are the lacecaps, so named for their flat heads which some say resemble a cap. The center of the lacecap has small, budlike blooms and larger florets around the outside. Mopheads and lacecaps require identical care.
The first highly publicized remondent (or reblooming) macrophylla, "Endless Summer," was introduced commercially in 2003. Praised for blooming on old and new wood, "Endless Summer" was a true breakthrough for areas that experience deep freezes.
Unable to locate "Endless Summer" locally, I ordered one online. I was disappointed with its performance in my garden and, according to some blogs I have read, I am not alone. It never really flourished, and I have since sent it to the compost. Fortunately, this group of hydrangeas is not necessary in our Mediterranean climate.
That online order experience opened my eyes to a whole world of newer hydrangea cultivars that are coming to market, but are not so common in our local nurseries. I ordered two recently introduced hydrangea paniculata cultivars, and I am captivated. "Little Lamb" makes me smile each time I look at it. The name derives from the appearance of a flock of dancing lambs on a fully blooming plant.
The whimsically named "Pinky Winky" is delightful in that it first blooms in pure white and than changes to pale pink and then a deeper pink as it continues to develop. The flower head can easily extend to 14 inches and the bloom season extends well into the fall. In a five-year trial of 47 hydrangea paniculata cultivars, "Pinky Winky" received a highly coveted 2008 Royal Horticulture Society Award of Garden Merit.
Paniculata cultivars, sometimes referred to as hardy hydrangeas, are extremely easy to grow in common garden soil, are much more drought tolerant than macrophyllas, bloom on new wood and can be pruned most any time except when the flower heads form in the summer. My experience has been that they are slow to wake from dormancy, but compensate by blooming far into the fall. They can also grow quite large — as tall as 8 to 10 feet — but can be kept compact by regular pruning, almost to the ground, in late winter or early spring.
Another newish member to my garden is "Lady in Red." I had read about this one in numerous catalogs and was delighted to stumble upon one in a local chain store at an attractive price. Lovely pale pink, lacecap blooms gradually turn to a burgundy rose as they mature, and the foliage is extremely attractive on its own. Sturdy red stems support distinctive dull green, red-veined leaves that turn to a gorgeous purple-red in the fall. It performs best in partial shade and is a rather compact grower. A macrophylla cultivar, "Lady in Red" needs little pruning, and none after July or August or you will risk cutting off next year's bloom.
I also ordered "Annabelle," a hydrangea arborescens or native American "smooth leaf hydrangea" from an East Coast nursery. "Annabelle" first opens as a truly white, large, drumstick bloom on a thin stem. The bloom then turns to a soft green, then later, back to white. The challenge is in providing support for these enormous blooms on spindly stems. Known for dropping or falling over after summer rains, I had never experienced this problem until this year's rather remarkable June rain. The profuse blooms of "Annabelle" lay draped over the garden wall, never to upright themselves. I've gathered arms full for bouquets as they look rather pathetic lying down. Knowing that significant summer rainfall is fairly rare here, I'll leave "Annabelle" where it is and perhaps prune the stalks a bit closer to 1 foot this spring in hopes of keeping the flower stems a bit shorter.
A new improved version of "Annabelle" has recently been released and promises to offer the biggest flowers and strongest stems of any of the "Annabelle" hydrangeas. Incrediball is advertised as a descendent of "Annabelle," producing basketball-sized blooms on sturdy stems.
Now is a great time to scour local nurseries and peruse garden catalogs and websites for fall planting. Hydrangeas are really hot these days with "new and improved" varieties of our well-loved classics constantly coming to market.
The University of California Marin Master Gardeners are sponsored by UC Cooperative Extension. For questions about gardening, plant pests or diseases, call 499-4204 from 9 a.m. to noon, and 1 to 4 p.m. weekdays, or bring in samples or pictures to 1682 Novato Blvd., Suite 150B, Novato.
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