Historical Tree Spotlight: A Black Pine from Dr. Yee-sun Wu

The National Bonsai & Penjing Museum is home to a breathtaking penjing collection housed in the Yee-sun Wu Chinese Pavilion. This month’s Historical Tree Spotlight draws your attention to a Japanese black pine (Pinus thunbergii) from Dr. Yee-sun Wu, whose trees initiated the foundation of the Museum’s Chinese collection and who financially supported the pavilion’s construction. 

A prominent penjing collector, Wu began styling the pine in 1936 and donated it in 1986, along with 23 other trees of various species. Read more about his personal background here. 

This Japanese black pine can be categorized as a tree penjing. “Penjing” refers to scenic landscapes created in trays or ports that often include additions like rocks and ceramic figurines, like a Chinese landscape painting come to life. A pot with a single tree can be called a “tree penjing” but is more commonly known as “penzai,” the Chinese pronunciation of the characters of “bonsai.” 

The pine’s exaggerated primary branch, the lowest and longest branch off the right of the tree, is a distinct Chinese tree penjing quality, James said.

“If your eye follows the curvy line of the trunk up and then down that swooping branch, you can see that it gives a playfulness or a whimsical look to the tree,” he said.  

Many of Wu’s penjing were trained in the Lingnan style – the clip and grow technique – which his father and grandfather are credited with popularizing. James said the dramatic change in the tree’s direction, led by the primary branch, is consistent with the aesthetics of Lingnan style. The sweeping movement emulates Chinese brush paintings and drawings that, along with scholarly pursuits of poetry and culture, have inspired penjing artists for hundreds of years. 

“If you look at a lot of old paintings of trees in China, there are sharp zig zags in the branching with a lot of natural breaks and snaps left in the painting,” he said. “It shows the weathering of the tree and its survival through time.”

This pine inspired the logo used on the cover of a booklet listing the trees Wu gave to the Museum in 1986.

A shot of the pine in its original pot from Wu's second publishing of his book.

Lingnan style technically means “south of the mountains” and strives to reveal but not control the nature of each tree specimen. Because the style encourages spontaneity and whimsy, these penjing appear more natural than bonsai, James said. 

He added that the black pine was likely collected and placed in a pot, like many Lingnan trees, rather than grown from seeds. The original pot is a traditional deep penjing container that fosters strong tree growth, which is useful when trees are first developing. Now that the penjing is more mature, it tolerates the shallowness and size of its current pot, which retains water well and restricts root growth, facilitating shorter branches.

Wu wrote in his book Man Lung Garden Artistic Pot Plants: “The challenge of art in penjing consists of uniting within the same pot the three elements from Chinese proverbs: ‘heaven, earth and man.’”

Caring for the pine

James hesitates to categorize this tree as completely Lingnan because black pines will die if they are constantly clipped back. Evergreens, like black pines, are typically treated with decandling, or the process of removing a first flush of foliage growth to create a second flush of needles shorter than the first. Shorter needles are in better proportion to small trees in containers and increase the trees’ ramification, or number of branch bifurcations, James said.

He added that Museum staff do the bulk of the work on this black pine between June and July, when decandling should be performed. Decandling the pine too early would produce lengthy needles in its second flush of growth, but decandling too late doesn’t give the second growth spurt time to harden before winter.

From August on, James and the Museum team remove old needles with fingers or tweezers. Black pines in the wild retain needles for multiple years, but James said they must remove the older needles periodically to help light filter through the top of the tree to lower foliage.

 “We pull more needles in stronger areas and less in weaker spots,” James said. “This practice makes the black pine look neater and balances the growth.”

Museum Donors & Their Trees: Dr. Yee-sun Wu

The National Bonsai & Penjing Museum is home to impressive trees from collectors and masters around the world. Among that amalgam of donors is Dr. Yee-sun Wu, one of the most prominent penjing connoisseurs and stylists. 

Dr. Wu was raised in a family that had practiced penjing for generations. He was born the eldest of 13 brothers and sisters in the Guangdong province of China. To support his family during the Great Depression, Dr. Wu started a bank in Hong Kong called Wing Lung Money Exchange – “Wing Lung” meaning “long-lasting harvest” or “good business.” 

The organization has grown over the decades into a multi-story, highly respected business in central Hong Kong and Kowloon now known as Wing Lung Bank. But Dr. Wu retired from the bank business at the end of World War II after his health declined and he was forced to rest.

During this period, he devoted all of his time to studying traditional penjing, creating a new persona for himself as “Man Lung,” or “scholar-farmer.” In 1967 in Kowloon, Dr. Wu and a few friends created the Man Lung Garden to display trees and serve as a forum for discussion about penjing. The Chinese government eventually acquired the land in the 1970s to build a railway station, but the garden was established at the Hong Kong Baptist University again in 2000.

In 1968, Dr. Wu printed 10,000 copies of his book the Man Lung Garden Artistic Pot Plants, his international term for penjing, to discuss the features of the garden and the ideology, history and celebration of artistic pot plants. 

He was one of six honorees at the Fuku-Bonsai Center International Honor Role in 1990. 

Dr. Wu, who died in 2005, is survived by 13 children and almost 40 grandchildren and great grandchildren in Hong Kong. 

Traditional styling 

Former NBF President Felix Laughlin said servicemen returning from their stations in Japan after World War II brought bonsai knowledge back to the United States. But he said many people didn’t realize that the tradition of penjing, the Chinese word for bonsai, could be traced back hundreds of years to China. 

Dr. Wu popularized traditional penjing, in the Lingnan style, throughout the Western world. Laughlin said Japanese bonsai artists often rely on wire to place branches in different positions, repeatedly replacing the wire as it cuts into the wood. Penjing artists like Dr. Wu tend to use the “clip and grow” technique, pruning again and again to determine branch placement, he said.

“You can tell bonsai have been heavily influenced by human care and training, while penjing are much wilder looking and free form,” Laughlin said. 

 Read more about the differences in the art form through our interview with Zhao Qingquan.

Dr. Wu’s trees

The penjing master curated a collection of more than 300 trees, which he donated to various institutions across the world. One can view Dr. Wu’s works in collections in Canada, Hong Kong, China and the United States. 

Former U.S. National Arboretum Director Dr. John Creech was familiar with Dr. Wu’s excellent penjing collection. He sent Col. John Hinds, a retired military officer who was heavily involved in the bonsai community, to visit Dr. Wu in Hong Kong to inform him about the plans to curate a collection in the United States. 

At first, Dr. Wu was impressed with the idea but thought his tropical trees would be better maintained on the West Coast, where the climate is more similar to Hong Kong and wouldn’t have cold winters like Washington, D.C. In 1983, Museum volunteer Janet Lanman wrote to Dr. Wu to renew the request that he display penjing at the Arboretum, assuring him that they could provide adequate winter protection for his trees. 

In July 1986, the Arboretum received 31 penjing from Hong Kong – 24 from Dr. Wu and seven from his colleague Shu-ying Lui. Dr. Wu provided a generous monetary gift for NBF and the Arboretum to construct the Yee-sun Wu Chinese Pavilion and even sent over some workers from Hong Kong to help with the details of the project. 

Although the Museum remains closed to protect staff and visitors during the spread of COVID-19, you can spot Dr. Wu’s trees online under our Chinese collection.

Species Spotlight: Chinese Elm (Ulmus parvifolia)

The interesting pattern which gives Lacebark Elms their name.

The Chinese Elm, also known as Ulmus parvifolia or Lacebark Elm, is a deciduous tree species native to China, Korea and Japan. The name Lacebark Elm refers to the interesting pattern created as parts of the tree’s bark flake off with age. This elm is a very hardy species that can grow in moist or dry soils – these trees can survive in USDA Hardiness Zones 4 through 9 – and thrive in hot urban environments. 

The elms typically have an upright trunk with a wide round canopy, and the average height is about 70 feet. This species is also resistant to diseases and pests, like Dutch elm disease and Japanese bark beetle. Three different Ulmus parvifolia are located at the National Bonsai & Penjing Museum.

This Chinese Elm, a penjing donated by Dr. Yee-sun Wu in 1986, resides in the Chinese Collection. The elm has been in training as a penjing since 1956 and was planted in the “rock-clinging” style. In this composition, a beautiful piece of Ying Tak Stone was placed vertically and two Chinese Elms were set in the natural contours of the stone. 

The trunk line of the tree on the left moves leftward up the rock to a wide, rounded canopy. The smaller tree on the right provides foliage mass and adds directionality to the overall composition. The beautiful blue antique container contrasts with the orange-red fall foliage, which can be seen in the late fall months at the Museum. 

Our second Chinese elm, also from the Chinese Collection, was donated by D.C. Metro native Stanley Chinn in 2002. The training age of this tree is unknown, but based on the trunk diameter the tree appears to have grown in the ground for decades before being put into a container. 

The style of this tree is “windswept” or “wind blowing”. The elongated branches on the left and the short branches on the right create the illusion of a powerful wind blowing on the tree from the right side. The interesting and exciting windswept style simultaneously depicts gracefulness and denotes strong environmental conditions.

The last Chinese Elm composition is a wonderful landscape planting, which is part of the Chinese Collection. Penjing Master Yunhua Hu donated the composition in 2004 after he created it earlier that year at the U.S. National Arboretum’s Penjing Symposium. This is an excellent example of penjing in which not just a single tree is displayed, but a combination of trees, understory plants, stones and figurines. The intricate design demonstrates how using multiple smaller trees can create a large and pleasing display. 

The movement of the whimsical trees guides the viewer to settle their gaze on a small stream with a gentleman fishing. The stream pulls the viewer in and provides a nice break between the larger and smaller groupings of trees, adding to the overall directionality of the whole composition. 

Ask to see the outstanding examples of Chinese Elms in our collection on your next visit to the Museum!