The Great Hydrangea Mystery
A couple of hydrangeas--one pink, one pale blue--are coming into flower in a garden we know, which surely means that summer is almost here. We associate the opulent foliage and the mounds of flowers with vacation cottages, wicker furniture, shaded parks, but its range covers most of the world, and its blooms can be controlled in greenhouses to match almost any season.
The first Westerner to see hydrangeas was a member of a Dutch trading party working on an island in Nagasaki harbor in 1776, probably unaware of what was going on at that very moment in North America. James Bauml, senior biologist and taxonomist at the Los Angeles State and County Arboretum in Arcadia, did some research for us but could not find out when the plant made its way westward--first to Europe, then to the United States. He could tell us, however, that the name derives from the Greek hydor for water and aggeion for vessel, and we suppose that there is some similarity to a water vessel. By the beginning of this century “no home was complete without its hydrangea,” and the more “colossal” the blooms the better, according to the late Victoria Padilla in her celebrated book, “Southern California Gardens.”
Hydrangeas are propagated commercially in Southern California both as a florist specialty item and for outdoor planting. Both markets are seeing a surge of interest.
Many of the hydrangeas in full bloom for Easter or Mother’s Day are the handiwork of Steve Barkwell, chief hydrangea grower at the Paul Ecke Poinsettia Ranch in Encinitas. He grows as many as 60,000 a year in a year-long strategy targeted on the changing date of Easter. “You have to think way ahead on colors and numbers,” he said. A year ahead, in fact. He takes cuttings from the mother plants in mid-April. After four weeks in the greenhouse, they are rooted and can be moved to open areas protected by plastic cloth that provides 40% shade. They are pinched back in late summer, and, when cooler fall weather encourages the plants to set buds, all of the leaves are stripped away and the plants are removed to a refrigerator where a constant 40-degree temperature is maintained. They are moved to greenhouses 75 to 90 days before Easter or Mother’s Day. Greenhouse temperatures can be controlled to accelerate or retard the flowering.
Rick Wells, propagation manager at the Monrovia Nursery Co. in Azusa, directs a somewhat smaller operation entirely outdoors, for his hydrangeas are for the home-garden market. He currently is propagating nine varieties--at least 2,000 plants of each. He has been impressed with how hardy the plants are, even in the heat of Southern California, once they are well established and as long as they are protected from the afternoon sun. They do not even seem to mind the air pollution.
Hydrangeas are pink or red when grown in neutral soil. Horticultural lime or superphosphate reinforces the pink and red shades, while a few months of exposure to acidic soils, easily engineered with applications of aluminum sulfate or acid food, will convert them all to shades of blue and lavender. There are those who put rusty nails around their plants to bring out the blue. The gardener who tends the hydrangeas that we have been watching, who does not use nails and thought that he was giving equal treatment, has no idea why one is pink and one blue, although only a few feet separate them.
