Cherry BlossomsRestoring a
Resplendent cherry trees from Japan ring the Tidal Basin at Washington,
Every year, nearly 600,000 tourists come to see the cherry blossoms in
Washington, D.C. They bring money to the local economy and take home
photographs and memories of the beautiful blossoms.
Future visitors will have the U.S. National Arboretum in Washington to thank
for a special gift500 cherry trees propagated from the Yoshino trees
presented by Japan to First Lady Helen Herron Taft in 1912.
Over the past 2 years, arboretum horticulturist Ruth L. Dix has grown the
new trees, Prunus x yedoensis, from cuttings taken from the original
Yoshinos. Those were given as a thank-you to President William Howard Taft for
his support of Japan during the 1905 Russo-Japanese War, when he was U.S.
Secretary of War.
Trees don't live forever, and Yoshino cherry trees average 40 years. The
surviving trees from the 1912 gift that surround Washington's Tidal Basin will
be 87 years old when their blossoms open this spring. Not unexpectedly, it's
estimated that only 125, or about 4 percent, of the original trees remain.
Last spring, a Washington Post newspaper article quoted retired
National Arboretum botanist Roland M. Jefferson and other botanists and
landscape architects as saying something should be done to preserve the
original cherries. In the 1980s, Jefferson devoted the last years of his career
to collecting, evaluating, and preserving flowering cherry germplasm, in
collaboration with the arboretum's shrub-breeding research program headed by
the late Donald R. Egolf.
"We really didn't have a program to propagate replacements from the
original trees. We just maintained the population from the commercial
nurseries," says Robert DeFeo, the National Park Service's chief
horticulturist for the National Capital Region. In the 1930s, William Clarke of
the W.B. Clarke Nursery in San Jose, California, gave a seedling selection of
Yoshino called Akebono (meaning daybreak) for planting around the Tidal Basin.
Those trees have pink flowers.
DeFeo says the Park Service keeps the Tidal Basin covered in springtime
pinks and whites through its "Blossoms for Our Future" program, which
receives contributionsoften given as memorialsto replace dying
trees with American nursery stock. But he says the National Park Service
understands why people get passionate about historic trees.
Resplendent cherry trees from Japan near the Washington Monument in Washington
"There is a movement in the United States to preserve so-called witness
trees," says DeFeo. "The sycamore that stood during the Battle of
Antietam is another example. Employees with the National Park Service see that
sycamore or the Yoshino cherries as giving living testimony, and they treat the
trees like children," he says.
When the Post article came out, arboretum director Thomas S. Elias
and National Park Service officials decided to ensure the survival of the
remaining original cherry lines. "Tom Elias was great," DeFeo
recalls. "He called me up and said, 'Just let us know what we can
Elias put DeFeo in touch with Margaret R. Pooler, a geneticist in the
arboretum's Floral and Nursery Plants Research Unit. Pooler and DeFeo decided
they should start taking cuttings right after cherry blossom time.
Complications pushed back the date to June 20close to the end of the
optimal time for cuttings. But Pooler knew that if the cherry trees could be
propagated, Ruth Dix could do the job. Dix had already successfully propagated
cherry trees at the U.S. Naval Observatory that were part of the original 1912
It had taken two attempts to bring the cherry trees to Washington in 1912.
The first shipment was diseased and had to be destroyed. The second contained
3,020 treesmainly Yoshino and some later blooming Prunus
serrulatafar more than the Tidal Basin could accommodate.
"The trees were too crowded, so they replanted some at other Washington
landmarks, such as the Supreme Court, U.S. Naval Observatory, and Library of
Congress," says DeFeo, who used to work with Jefferson at the arboretum.
"The library didn't even know what they had until Roland found the records
and told them." Those little-known plantings provided researchers a means
of differentiating original trees from later replacements around the Tidal
Basin and were an invaluable second source of original material for
Horticulturalist Ruth Dix (left) and geneticist margaret Pooler check the
progress of 2-year-old trees propagated from the historic Yoshino cherries
given to the United States by Japan in 1912.
"We couldn't be too choosy," says Dix of her time gathering
cuttings at the Tidal Basin. "For any living thing, renewal and
regeneration get harder as it agesand these trees had already lived twice
their normal lifespan."
Willing and Able Support
Cost was a significant factor in the propagation effort, which included
fingerprinting of DNA by Pooler to help confirm the trees' identity.
The project was financed in part by the J. Frank Schmidt Family Charitable
Trust established by J. Frank Schmidt & Son Co., a wholesale grower of
shade, flowering, and ornamental trees in Oregon.
"The cherry trees in Washington, D.C., are a national treasure,"
says Jan Schmidt Barkley, who chairs this trust that supports horticultural
research and education across the country. "The nursery industry and the
public have benefited from the U.S. National Arboretum's work. We have been
happy to give back by underwriting the propagation effort."
The nursery is also testing new cherry tree hybrids developed by Pooler and
her predecessor, Egolf.
"It is exciting to us that Dr. Pooler is working on cherry breeding;
it's very important to the nursery trade," says J. Frank Schmidt's
horticultural expert, Keith Warren. "We are evaluating several of her new
cherry cultivars here in Oregon. We feel her work has great potential."
Cherry trees have a beauty and compact size many urban gardeners like, but
they are vulnerable to insects, diseases, and flooding, Warren says.
"That's why Pooler's work to toughen these trees up is so valuable."
Stronger cherries would require less fertilizer and pesticides.
Warren says that woody ornamentals are important not only to his company,
but also to the economic well-being of his entire state.
Resplendent cherry tree blossoms for Japan near the Tidal Basin at Washington,
"Nursery crops are the number-one moneymaker in the state of
Oregon," he says. "Last year, in terms of dollars earned, they
brought in more than barley, wheat, or cattle."
This kind of research will become even more important with the growing
environmental horticulture industrywhich includes trees, bulbs, and other
outdoor landscaping plants. It has mushroomed from $4.6 billion in 1986 to $6.9
billion in 1997.
But while Pooler's efforts may focus on new ornamental cherry hybrids, she
is also exploring the genetic value of the 1912 trees. The ones still living
may be extremely well-suited to city lifeanother potentially marketable
"Cherries are small trees and undeniably beautiful. As landscapes
become smaller they're going to be more in demand," says Warren.
At the Root of Good Cuttings
Most people think of taking cuttings as simply breaking off plant stems and
placing them in water. Saving antique cherry trees, however, requires a lot
more care. Dix brought years of experience to the task.
"You look for the most juvenile new growth," she explains.
"Many people think the top of a tree is the best place for cuttings, but
that's not always the case."
Dix performed the delicate task of turning hundreds of cuttings, carefully
wrapped in wet towels and stored in an ice chest, into 500 healthy trees.
First, she cut them into smaller parts. Then, "To start propagation, I
made a wound on the stem at the base of the cutting," she says. "The
wounding process actually creates more surface area for the rooting hormone to
First Lady Nancy Reagan presented a regrown Yoshino cherry tree to Japanese
Ambassador Yoshio Ogawara during a White House ceremony in January
Afterward, she planted the cuttings in a growing medium on a greenhouse
bench equipped with an automatic misting system. Artificial mesh leaves
triggered the mist when they dried out.
All of Dix's work paid off with an 80-percent rooting success rate.
"You always feel so exhilarated when you see your cuttings take
root," says Dix. "Plus, it makes you feel really good to be part of
But as the trees grew, Dix had to turn from tender loving care to tough
love. Most cherry trees have weak apical dominance, which basically involves
hormones instructing one branch to become the main stem of a tree. Some cherry
trees would be happy enough just being cherry bushes.
This meant Dix had to cut off stray, straggling branches and stake the trees
to bamboo poles to grow them into upstanding members of the Tidal Basin
The new trees will be a welcome addition, but they do present DeFeo with a
challenge. Genetic authenticity is great, but too little genetic diversity in a
planting leaves the trees vulnerable to diseases and pests.
"The guideline is to plant less than 10 percent of the same species, 20
percent of the same genus, or 30 percent of the same family," says DeFeo.
"But I'm working with 100 percent species similarity, so I need all the
diversity I can get."
Pooler's DNA work will help uncover whether the trees have subtle genetic
differences. It will also confirm DeFeo's hunch that there are some genetic
differences in the trees and help him plan which trees might need extra
protection in the future.By Jill
Lee, Agricultural Research Service Information Staff.
This research is part of Plant, Microbial, and Insect Germplasm
Conservation and Development, an ARS National Program described on the World
Wide Web at http://www.nps.ars.usda.gov/programs/cppvs.htm.
Margaret R. Pooler and
Ruth L. Dix are with the
USDA-ARS U.S. National
Arboretum, 3501 New York Ave., N.E., Washington, D.C. 200021958; fax
(202) 2454575, phone [Pooler] (202) 2454568, [Dix] (202)
The Cherries' Champion
Botanist Roland M. Jefferson has always loved Japanese flowering cherry
trees. And he's shared his passion with the worldfrom the Adachi Ward of
Tokyo to the Tidal Basin in Washington, D.C. It was at the Tidal Basin that
Jefferson fell in love with the historic 1912 Yoshinos, as an 11-year-old on a
family outing in 1935.
After serving in World War II, Jefferson earned a degree in botany in 1950
from Washington's Howard University. "I'd been accepted in dental school,
but I never answered," he says. "I knew I wanted to work in botany,
so I accepted a job at the U.S. National Arboretum."
Even with his degree, the only job he could get with the arboretum in 1956
was labeling plants. And though he was promoted to botanist a year later, it
wasn't until 1972 that he began cherry tree research.
"I felt lucky that no one was doing anything on the history of the
cherry trees," he says. "I went to the National Park Service, the
National Archives, and other libraries, assembling thousands of records that I
put together into a history."
The Japanese Flowering Cherry Trees of Washington D.C.; A Living Symbol
of Friendship caught the attention of Tadashi Furusho, who was then mayor
of the Adachi Ward section of Tokyothe very place where the Japanese
obtained cherry trees to give to the United States 87 years ago.
Mayor Tadashi Furusho of the Adachi Ward section of Tokyo invited former U.S.
National Arboretum botanist Roland Jefferson to Japan to tour the park where
1,200 Yoshino cherry cuttings Jefferson had helped take would be planted.
In 1980, the mayor sent a three-member team to visit the director of the
arboretum, John L. Creech. They wanted to meet Jefferson. They had in mind a
friendship park that would be filled with cherry trees.
But Yoshinos had become rare because of World War II damage and subsequent
development. The National Park Service had provided some cuttings to the Adachi
Ward earlier, but more were needed. Jefferson already had a solution.
"As part of my studies, each year I recorded the blooming dates of
Potomac Park cherries," says Jefferson. "Over time, I could see the
original trees were aging and dying. So I got permission to take cuttings, and
I propagated over 100 trees between 1976 and 1979."
One of those trees was presented to Japanese ambassador Yoshio Ogawara in
1981 by First Lady Nancy Reagan. It was named the President Reagan cherry tree
by Gov. Shunichi Suzuki of Tokyo. Mayor Furusho then invited Jefferson to come
to Japan to see the Toneri Park grounds where the Reagan cherry and 1,200
cuttings that Jefferson had helped take would be planted.
"The Reagan cherry is doing well," says Kiyoshi Hashimoto, who
tends the tree. "Many people come to see it bloom every spring."
Before retiring in 1987, Jefferson made several trips to Japan, collecting
more than a half million seeds between 1982 and 1986. His efforts have brought
genetic diversity to American cherry treesa protection against future
diseases, pests, and flooding. He has also found blossoms of spectacular
Jefferson continues to help save the Potomac Park cherry trees in
Washington. And last April, Adachi Ward members brought him back to Toneri
Park, where the trees are now taller than he is.By
Jill Lee, Agricultural Research
Service Information Staff.
Roland M. Jefferson is retired from the U.S. National Arboretum and
currently lives in Seattle, Washington. He recently donated his historic
research papers and letters to the arboretum's library. For more about the
majestic Yoshinos, contact the arboretum at (202) 245-4539.
"Cherry BlossomsRestoring a National Treasure" was
published in the April 1999 issue of
Agricultural Research magazine.