Historical Tree Spotlight: A Cork Bark Collaboration

Parent and child style cork bark Japanese black pine. Photo courtesy of the U.S. National Arboretum.

For this iteration of our Historical Tree Spotlight series, we unveil the history and creative process behind a special cork bark Japanese black pine ( Pinus thunbergii ‘Corticosa’), which is truly a rare specimen. It is a variation of the conventional Japanese black pine (P. thunbergii) found in coastal Japan and South Korea. The cork bark variety of black pine has an overly active cork cambium that makes an already rugged barked pine a novel wonder. The tree prefers mild climates and makes for a popular and aesthetically pleasing choice for bonsai enthusiasts.  

You can check out the cork bark bonsai above at the National Bonsai and Penjing Museum. It is in a parent and child style configuration that has been in training since 1980, when two prunnings from another cork bark pine bonsai in the Museum’s collections were grafted to a Japanese black pine rootstock. The trees represent a mature parent tree in the wild that has given rise to a younger succession which has thrived under the larger tree's protection, yet reaches toward the light to become its own presence in the woodland. 

Read more about the Japanese Black Pine here in our Species Spotlight.

The textured bark of the cork bark variety provides an enhanced and unique look to this bonsai classic.

“The overall ruggedness of black pines in general is valued in bonsai culture, but the cork bark has the next level of barking that really makes this rare and prized,” says Museum Curator Michael James.

One of the cork bark Japanese black pines in 1989  after being grafted by Robert Drechler. Photo courtesy of the U.S. National Arboretum.

The origin of this tree begins in 1980 with the Museum's very first Curator, Robert Drechsler, who passed away late last year. Since cork bark black pines are difficult to propagate, Drechsler used his skills as a talented horticulturist to graft a branch of the cork bark variety onto a conventional black pine rootstock. Dreschler placed the graft low on the base of the trunk, as the difference between black pine and cork bark is so dramatic that a high graft will cause an undesirable inverse taper due to the thickness of the corky bark.

The addition of a second tree was performed in 1999 by the Museum’s second Curator, Warren Hill, creating the parent and child, or twin trunk style we see today. A later curator transplanted the bonsai into a round container made by the American ceramicist, Ron Lang.   

“This tree is a good example of the collaborative art that bonsai is,” says James. “The media is a living organism and has a lifespan longer than the average human. It requires multiple people in continuum to care for, shape and form.”

The main tree in 1989 before its current multi tree configuration by Warren Hill. Photo courtesy of the U.S. National Arboretum.

The Cork Bark Black Pine exemplifies a core mission of the U.S. National Arboretum, as it is a rare specimen of plant DNA. The arboretum collects, conserves and distributes plant germplasm, acting as a library of sorts. Their repository of genetic information benefits both the scientific community and the public good. 

James also credits the impact of this flourishing tree to the work and influence of Robert Drechsler.

“Robert Dreschsler said, ‘we can only hope we've left something behind that will live on,’ and I think it's definitely true in his case,” says James.

Drechsler’s grafted cork barks were originally a part of the Museum’s Education Collection. What started as a bonsai experiment and tool of education has become a collaborative artistic expression. The bonsai has been removed from the Education Collection and placed into the more permanent North American Collection.

Museum Curators: Jack Sustic

Jack Sustic at NBF’s annual reception in 2018.

“It’s almost as if my life path was leading, from the very beginning, to become curator.”

— Jack Sustic

Sustic has just retired from his two-year stint as National Bonsai Foundation co-president and 19 years as a board member, leaving an extensive and inspiring legacy at the Museum – including 12 cumulative years as Museum curator. Therefore, it’s only fitting we pay homage to him in our next Museum Curators spotlight. 

His “path” to bonsai curator began indirectly during his youth. Sustic had heard references to bonsai in films like Karate Kid, but he first saw a real bonsai in the mid-1980s when he was serving in Korea as a U.S. Army soldier before college. He said the bonsai immediately captivated him, and upon returning to the U.S. at Fort McClellan, Alabama, Sustic joined the Alabama Bonsai Society.

The club jumpstarted his love for bonsai and plants in general, and Sustic soon graduated from Michigan State University with a degree in horticulture. He scored his first plant care job at the Riverbanks Zoo and Botanical Garden in South Carolina, during which he applied for the U.S. National Arboretum’s internship at the National Bonsai & Penjing Museum.

In 1996, Sustic served as the Museum intern for six months under Curators Bob Drechsler and Warren Hill. He returned to South Carolina after his internship wrapped up but was soon chosen for the Assistant Curator position, taking over as curator after Hill retired. Sustic served as curator from 2001 to 2005 and returned in 2008 to preside over the Museum for another eight years. 

“It was such an honor to be part of that collection, but with that honor comes responsibility,” Sustic said. 

Sustic and volunteer Dr. Joe Gutierrez repotting the Yamaki pine.

Accomplishments as Curator and Co-President

Sustic helped to establish many perennial programs and relationships at the Museum and NBF. He pioneered the formation of NBF’s National Bonsai Hall of Fame, which currently includes three members: John Naka, Yuji Yoshimura and Bill Valavanis.

“It was something I thought the Museum and the U.S. bonsai community needed in order to honor and recognize these bonsai masters’ valuable contributions to the art,” he said. 

Sustic is credited with planting the seeds to grow the Museum’s Sister Museum relationship with the Omiya Bonsai Art Museum after he visited their site in Saitama, Japan. Sustic also formed the Consortium of Public Bonsai Curators as a way for bonsai artists and leaders to share information about how they share, cultivate and protect their bonsai collections. 

“The consortium serves to help each other and each public collection. I’m very proud of that,” he said. 

From left to right: Former Curators Jim Hughes, Bob Drechsler, Jack Sustic and current Curator Michael James.

Sustic’s Bonsai Inspirations

Sustic met an array of friends and teachers throughout his nearly 20 years at the Museum. 

“Being curator has allowed me to get to know, work with and befriend people around the world who have been part of the Museum,” Sustic said. “The kindness that all these people share is wonderful.”

Among that company is Felix Laughlin, appointed as NBF’s third president as Sustic began his internship in 1996. Sustic eventually joined Laughlin as co-president from 2018 to 2020. 

“I was really lucky to have one NBF president the entire time I was at the Museum and really lucky it was Felix,” Sustic said. “He is such a wonderful guy, and we worked really well together.”

Sustic learned the art of bonsai from many people, but he most prominently drew inspiration and learned from bonsai master John Naka, who visited the Museum every year to work on trees, especially his world-renowned “Goshin.” Sustic also visited Naka in California to work on trees in Naka’s backyard. 

“Looking back now, I wish I had paid more attention,” he said. “It went by too fast, but those were wonderful experiences. I learned a lot from John, so his influence was huge on me.”

Sustic also learned from Harry Hirao and traveled to Saburo Kato’s bonsai nursery in Japan called Mansei En, during which he received one-on-one training from Kato. With their help, he excelled as a leader and friend throughout his years of dedication to the Museum. 

“I distinctly remember telling Bob Drechsler, ‘I don’t know how you can be curator. I could never do it,’” Sustic said. “Fortunately, over time I learned the ropes, and eventually I took it over. I considered it a real honor and privilege to have been the steward of those trees, and I still feel that way.”

Sustic adds the final touches on a trident maple prior to an official state visit by the Japanese Prime Minister in 2012.

Museum Curators: Robert Drechsler

Bob Drechsler, as curator of the bonsai collection, poses in 1987 for a picture in front of the juniper bonsai that inspired the design of the National Bonsai Foundation logo.

Welcome to our special blog series profiling the wonderful curators who have led us since the inception of the National Bonsai & Penjing Museum! Our first edition highlights the very first person to oversee the care of the Museum’s collections: Robert Drechsler. 

Drechsler began working at the U.S. National Arboretum in 1959 as a plant technician under Dr. Don Egolf. When Arboretum officials started planning a special celebration for the United States’ bicentennial that involved bonsai, Drechsler took a class at the Potomac Bonsai Association to become familiar with the art. 

He said the Arboretum originally asked someone else to take care of the incoming trees, but the person ended up not wanting the job. A government shutdown at the time meant nobody new could be hired to positions at federal agencies like the U.S. Department of Agriculture, which the curator role falls under.

Drechsler was already an Arboretum employee, so Director Dr. John Creech agreed he could serve as the first curator. But just because Drechsler hadn’t previously worked on bonsai didn’t mean he wasn’t prepared to take on his new role. 

“Trimming bonsai is an artistic form, and I had done flower arranging and such as a florist to work my way through college, so I had some idea of the artwork,” he said. “Plus, I had 17 years of work raising, trimming and caring for plants at the Arboretum.” 

Drechsler worked diligently to learn about bonsai, even spending six weeks training in Japan in 1977. He said Ruth Lamanna, a prominent member of the bonsai community, was especially helpful in developing his bonsai education. 

Drechsler helps unpack the newly-arrived crates of Japanese bonsai at the quarantine station in Glenn Dale, MD in April 1975.

Drechsler helped the two ladies care for the bonsai quarantined in Maryland, which used to house the U.S. plant introduction station. He worked on both the Japanese collection – the trees that started the Museum collections – and the trees U.S. President Richard Nixon brought back from his trip to China in the 1970s. 

Bonsai Master John Naka often stopped by to suggest bonsai care tips, like how to preserve deadwood on bonsai and penjing. 

“I took the ladies’ recommendations, and I gained more and more knowledge about the care of the plants, like repotting and soil techniques,” Drechsler said. “It was a learning experience I gained as the curator, rather than being knowledgeable about bonsai before the collection came.”

Former Arboretum Director John Creech speaks at the dedication ceremony for the Japanese Bonsai collection on July 9, 1976. Henry Kissinger, Secretary of State, is seated in the middle/right spot. Drechsler said this was one of the most memorable and impressive moments in his curatorship.

Drechsler said the best part of serving as curator was his ability to transform a group of unassuming plants into well-trimmed bonsai to present to the public. He said the ability and cooperation of volunteers was essential in maintaining excellent and appealing bonsai. 

Drechsler added that he loved to see groups that entered the Museum chatting loudly instantly quiet down in awe after setting their sights on the bonsai and penjing collections.

“Young kids would come in with their teachers, and they were thrilled that these ancient plants were that old,” he said.

Drechsler retired in 1996, after nearly 21 years of service to the Museum as the very first curator. He said he wanted to dedicate his free time entirely to leading the local masonic chapter. 

He occasionally volunteered at the Museum until a 2015 heart operation put him out of commission for volunteering. Drechsler has since focused his time on leading and partaking in the freemasonry fraternity.

LEFT: Drechsler hand-pollinates hibiscus in the Arboretum’s research greenhouse in 1964 when he worked as a research technician. RIGHT: Drechsler trimming a bald-cypress in the Yoshimura workroom in 2007 as a weekly volunteer.

“Bonsai brought the joy of working in an art form and the opportunity to enjoy an activity I’d like to do, but I was also paid for it, so I could make my living and have a retirement,” he said.

NBF honors Drechsler each year by funding the First Curator’s Apprentice program, which the Foundation created in 2011 to celebrate the National Bonsai & Penjing Museum’s 35th anniversary and to pay homage to Drechsler’s legacy as the original curator. Our 2019 apprentice Andy Bello now serves as the Museum’s assistant curator, and our 2020 apprentice is Sophia Osorio. 

“They knew I didn’t like my name on things, that I didn’t want it to be the ‘Robert Drechsler Apprenticeship,’” Drechsler said. “They did it as a nice gesture and a sort of thank you.”

NBF is grateful to Drechsler for taking the helm of the Museum and his incredible support of the bonsai community since. Our next profile will highlight his successor, Warren Hill, who oversaw the collection for the following five years.