WASHINGTON, D.C. — More than half a million visitors annually embark on a spring pilgrimage to Washington, D.C., to see the cherry trees in bloom.
Besides sheer profusion, those cherries have history. They were a gift from Japan as thanks for our help during the Russo-Japanese War of 1905. Howard Taft was secretary of war then; he was president when the first cherry tree was lowered into the ground in 1912 by his wife, Helen.
Alas, no tree lives forever, and those original cherries have been succumbing to age despite efforts to coddle them along. It wouldn't seem right to stick just any old cherry trees into the ground to replace those that fail. After all, these particular trees symbolize a bond with Japan and have stood witness to history. Besides, there are a number of different cherry species and varieties — not even all pink-flowered, or double-flowered or weeping cherries are the same.
The 3,000 or so trees sent as a gift in 1912 were mostly Yoshino cherry trees. Yoshinos are hybrids of unknown parentage, and come in a number of varieties, among them those with pink flowers and upright habit (Afterglow), white flowers and weeping habit (Pendula), and diminutive size and weeping habit (Shidare Yoshino).
The earliest replacements for ailing trees around the Tidal Basin were made in the 1930s and were of a Yoshino variety called Akebono ("Daybreak"), which has double, pink flowers.
THE CLONING SOLUTION
In recent years, efforts were made to replace ailing trees with genetic replicas of the originals. Such trees would be exactly the same as the originals, only younger. Genetic replicas are created by cloning, which involves taking cuttings from the original trees and rooting them to make whole new ones.
Rooting cuttings from an 80-year-old tree is not easy, because cuttings generally root most readily from so-called juvenile wood. Where do you find juvenile wood on an 80-year-old plant? In sprouts near the base, the original part of the plant.
Since not all of the original Yoshino cherries were identical, efforts have also been made to "fingerprint" them, using their DNA to better identify and differentiate them. The greater the genetic diversity that is found the better, because a narrow gene pool makes any planting more likely to be wiped out by pest problems.
Some of those original cherries are not even Yoshinos but so-called Japanese cherries, another species with a similar range in varietal characteristics. Kwanzan is perhaps the most famous variety of Japanese cherry.
Spring break blooms Washington's famous cherry tree blooms are expected to be at their best between March 26 and 30. The average peak bloom date is April 4, but last year's peak came earlier on March 20, due to the warm weather. National Park Service cherry tree expert James Perry says the trees are blooming a little bit earlier than 50 or 75 years ago. The cherry blossoms draw about 1 million visitors to the nation's capital each spring. This year marks the 101st anniversary of the gift of trees from Japan.