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Lacecaps are most elegant hydrangeas
By Norman Winter
Central Mississippi Research & Extension Center
At this time of year, you could plunk me down in a woodland setting surrounded by hydrangeas and I would be in total bliss. I love all types of hydrangeas, including the most elegant of all: the lacecap.
Each year I get three or four calls, emails or letters asking what went wrong with a hydrangea because it did not form a large, mophead shape. Sadly, these gardeners aren’t enjoying the exquisite beauty of this particular type of bigleaf hydrangea.
Nearly all lacecap and mopheads are the Hydrangea macrophllya, commonly called bigleaf or French hydrangea. Lacecap gets its name from its shape, which is flat and cap like rather than ball or mophead shape. The large flowers in the outer ring are sterile but serve to attract pollinators to the tiny flowers in the middle.
Outside my office there is a large lacecap that has received little if any attention for years, yet it blooms like clockwork and is a wonderful companion to the lower-growing native wood ferns.
There is a new lacecap sweeping the nation this year called Twist-n-Shout. I planted a small one last year and then forgot about it. Now as I come in and out my back door, I have colorful blossoms greeting me. I can hardly wait for it to reach mature size.
Twist-n-Shout comes to us from the same source that brought Endless Summer. It was hybridized by Michael Dirr of the University of Georgia and is a cross between Penny Mac and Lady in Red.
In addition to Twist-n-Shout and its parent, Lady in Red, look also for Mariesii, which comes in both green leaf and variegated forms. Blue Wave, Lanarth White and Geoffrey Chadbund are also popular.
In the South, hydrangeas prefer morning sun and afternoon shade in a rich, organic-amended soil followed by a good layer of mulch. Those grown in the North can tolerate a lot more sun. On particularly hot summers, you may find them wilting if not given some afternoon shade.
I grew up in Texas, where the hydrangea blossoms are hot pink, and I was astounded at seeing my first ones in the Southeast that were blue. The flower color of many hydrangeas is related to the aluminum available to the plant. In acidic soils, aluminum is available and the flowers are blue. In the alkaline soils, aluminum is not available and the flowers are pink.
It seems that gardeners always want the opposite of what they have. So if you have blue flowers and want pink ones, modify your pH by adding dolomitc limestone at a rate of about 1 cup per 10 square feet and water it into the soil. If yours are pink and you want blue, add 1/2 cup of wettable sulfur per 10 square feet and water in. This is not an exact formula as your soils may be at extremes. If this is the case, a soil test will come in handy.
Because hydrangeas are such fast growers, most gardeners ask about pruning to control size and shape. Remember that these hydrangeas bloom on old wood, so prune when the flowers begin to fade. Deadhead flowers and cut back as needed to make your plants bushy. Flower buds for next year begin to form in late summer, so do not prune in late winter as this will eliminate many of these flower buds.
In the woodland landscape, use them in bold drifts under trees and in combination with mondo grass, liriope, hostas and ferns. If you plant some this weekend, I feel certain their beauty will mesmerize you.