Assistant Curator’s Blog: Collecting Moss and Creating Top Dressing

As bonsai practitioners, we are always thinking about the past, present, and future aspects of our trees and the environments in which they live and grow. We constantly plan and prepare for the next step in the wonderful journey of bonsai and penjing. One preparation that can be completed any time of the year and is extremely important for the repotting process is collecting moss and creating top dressing. 

Bonsai and penjing are commonly grown in small containers with inorganic substrate, or the layer of matter that helps trees grow and obtain nourishment. The substrate National Bonsai & Penjing Museum staff uses consists of the Japanese clay substrate called akadama, pumice, and lava rock, although substrates like tree bark and perlite could be used.

This well-drained substrate retains water to provide to the tree while allowing oxygen to flow through the soil, keeping the containerized tree healthy. To ensure the health of bonsai and penjing, a practitioner must constantly check and carefully manage watering to maintain the delicate balance of oxygen and water.

Moss is cultivated on the substrate surface by applying a layer of top dressing. This dressing is composed of local mosses typically collected from places like parking lots, driveways, or a nearby forest. The mosses may be mixed with high-quality sphagnum moss for larger tree collections. The live and sphagnum mosses are then ground to a smaller size, and soil and fine particles are removed.

All you need to collect moss is a container, a scraping tool and scissors, shown here. 

The ideal moss is tight and low growing. Species that spread and climb will create issues when the moss grows up the trunks. This is especially problematic on rough bark trees, which will need to be sprayed carefully with vinegar to kill and remove the moss.

Once collected, place the moss in trays to dry, allowing for the soil and other fines to easily be sifted when grinding.

After the moss has dried, use bonsai substrate-sifting screens that are one-quarter, one-eighth, and one-sixteenth size. Take the moss and rub against the screens, starting with the one-quarter size. It may not be necessary to grind past the one-eighth size screen, depending on the size of the bonsai substrate, and the one-eighth screen can be used to remove the smaller particles.

The top left image shows the sphagnum moss before and after grinding. The top right image shows the locally collected moss before and after grinding. The bottom image shows both the ground sphagnum moss and the locally collected moss separately, as well as after mixing both together with about a one-to-one ratio.  

Spread a thin layer of topdressing to cover the fresh substrate after repotting is complete. 

Applying top dressing to the surface of bonsai and penjing at the end of the repotting process provides multiple benefits. The moss establishes the aesthetic of the composition, increasing its value. The moss layer also holds moisture in the top portion of the media, which would dry out much faster than the lower portion if left uncovered. The moss layer also helps prevent breakdown and erosion of the substrate in the container. 

Once you collect moss, the empty trays can be filled with soil and a layer of top dressing. This allows you to propagate specific moss varieties and avoid having to collect moss each year from other sources.

As important as moss and top dressing is for bonsai and penjing, you also want to remember to follow and stay within specific guidelines. Although it may seem and sound harmless, it is not always legal to collect moss in every area you find, so be sure to always ask permission and obey trespassing signs if you are collecting!

Sincerely,

Andrew Bello
Assistant Curator

The National Bonsai and Penjing Museum
U.S. National Arboretum

ASSISTANT CURATOR'S BLOG: Fall at the National Bonsai & Penjing Museum

Figure 1Trident Maple (Acer buergerianum) donated by Ted C. Guyger in 1990, in training since 1975.

Practicing the art of bonsai and penjing is rewarding in many ways, and each season provides a multitude of beauty, work, and lessons. As fall continues, all the hard work we bonsai practitioners have put in throughout the growing season on our deciduous trees is honored by an array of yellows, oranges, and reds.

Now in mid-to-late fall, we have a moment to breathe the cool autumn air and enjoy the vibrant colors. But like many things in life, this moment of visual pleasure and relaxation feels all too short lived. The pigments slowly begin to fade, and leaves tumble to our display areas, signaling that the next phase of seasonal work has arrived. 

Leaves dropping from our deciduous trees conveys that the stored resources in the leaves have been reabsorbed into the twigs, branches, trunks, and roots. This reserved energy will power our trees when they awaken to grow again in the spring.

Now we can begin tertiary structural pruning of many of our deciduous trees, like the much-beloved trident maples and other non-flowering species. This pruning process includes spotting twigs that have thickened in the outer canopy, detracting from the delicate, finely ramified structure we strive for. We also look for areas where more than two twigs are growing from one location, known as a node. By reducing these areas to two twigs, we can prevent unwanted swelling and promote a smooth transition of taper from the trunk to the tip of the twig. 

Ginkgo biloba – donated by Kiku Shinkai in 1976, in training since 1926

Lastly, we look at areas where twigs have elongated too far and prune them back to scale with the design of the tree. This work may be completed after the leaves are done changing color until late winter but should finish before the buds begin to elongate and open. If we prune during the dormancy period, we reduce the chance that new growth will be stimulated due to the removal of growth inhibiting hormones. We prune judiciously to perpetuate health and the execution of the design we have been working so hard to create.

While pines, spruces, and junipers don’t lose all their foliage, these conifers also need some attention before the onset of winter dormancy. Pines and spruces can now be cleaned of old needles, and their designs can be refined with wiring. Weaker foliage on junipers can be removed, and adventitious growth can be eliminated from the crotches of branches.

Cleaning out old needles and growth allows more light to enter the canopy and stimulate interior buds, helping them more strongly develop. Cleaning trees this time of year can be tedious, especially on a large collection, but I think this intimate operation brings us closer to our trees and gives us an even better understanding of their health and growth habits. 

This is also an important time to take advantage of the last warm months to ensure all winter preparation and some spring preparation is completed, and those techniques vary greatly. The simplest is arranging the area where trees will be placed on the ground out of the cold drying winds. Raised beds can be constructed to heel trees into mulch to protect the delicate root systems. Cold frames can be built and prepared to provide protection from wind and frost damage.

Cleaning buildings and testing heating and ventilation systems in greenhouses should be done to ensure all mechanisms are functioning properly. No matter the method of protection, be on top of this task before the temperatures dip below 40° F. If a random cold snap of 28° F or below arrives before everything is prepared for winter, the best thing for your trees is to place them on the ground for the night.  

American Beech (Fagus grandifolia) donated by Fred H. Mies in 2003, in training since 1979

Many other tasks may be completed at this time of year, but the ones shared above are what I feel to be the most important. As the leaves on all of the trees in the landscape and in our bonsai and penjing gardens begin to fall, and winter approaches, we, like the trees, must try to store our energy, shed our stress, and prepare for the challenging cold months ahead.

Sincerely,

Andrew Bello
Assistant Curator

The National Bonsai and Penjing Museum
U.S. National Arboretum

Species Spotlight: Cypress (Taxodium distichum, ascendens, mucronatum)

This month’s Species Spotlight (by our First Curator’s Assistant, Andy Bello) turns the light on three different species that constitute the genus Taxodium: Bald Cypress (Taxodium distichum), Pond Cypress (Taxodium ascendens) and Montezuma Cypress (Taxodium mucronatum). All three species are located in our collections at The National Bonsai & Penjing Museum. 

Old Bald Cypress (Taxodium distichum) at Lake Drummond, VA (Photo by Andy Bello)

Taxodium are extremely flood-tolerant, deciduous conifers in the cypress family Cupressacae. These trees can reach heights of about 100-150 feet and trunk diameters reaching more than 37 feet. A distinctive feature of taxodium is the formation of pneumatophores, also known as “cypress knees.” Some bonsai experts debate whether the knees aid in the uptake of oxygen or if they support the trees in wet soil conditions. 

Species history and general facts

Bald cypresses are mainly found along rivers with silt-rich flood deposits throughout the Southeastern United States and even up the Mississippi River into Southern Indiana. 

Pond cypresses live within the Southeastern Coastal Plain, from North Carolina to Louisiana, and grow in more stagnant blackwater rivers, ponds and swamps, rather than silt-rich flood deposits. 

Montezuma cypresses are found between the lower Rio Grande Valley down to the highlands of Guatemala. This cypress is a riparian tree that grows along streams and rivers. This species tends to be evergreen and not deciduous, given its distribution in a consistently warm climate. Montezuma cypresses on average have the largest trunk size, with some reaching about 37.5 feet in diameter.

Take a look at some of the cypresses we have at the Museum!

Bald Cypress

This bald cypress (Taxodium distichum) #269 is located in the North American Collection. It has been in training since 1972, and the late Vaughn Banting donated the tree in 2000. Banting originally purchased the tree as a nursery plant. This bald cypress, along with one at the Pacific Bonsai Museum, are the first two trained into a configuration Banting championed called “Flat Top Style.” The flat top style with knees protruding from the soil is a very distinctive trait of bald cypresses.

Read more about the history of this bald cypress, Vaughn Banting and the flat top style here.


Montezuma Cypress

This montezuma cypress (Taxodium mucronatum) #274, now located the North American Collection, was donated by Mike Naka in 2004 in honor of his grandfather and bonsai master, the late John Y. Naka. 

John Naka purchased this bonsai from a nursery in Los Angeles after traveling from Denver in 1946 and began training the tree in 1948. The bonsai is trained in the formal upright style to invoke the massive height and girth often seen in the species. By keeping the primary branches short and closer to the trunk, Naka provided an even grander image of the species’ height. 

Montezuma cypresses are evergreen in their native warm climate, but their seasonal beauty can truly be appreciated when they are allowed to thrive in Northern climates.

Pond Cypress (with bald cypresses)

This group planting of a pond cypress (Taxodium ascendens) and multiple bald cypresses (Taxodium distichum) #250 is located in the North American Collection. Jim Fritchey and Dick Wild donated the planting, comprised of trees collected from the wild Floridian swamps, in 1990 after arranging the original planting in 1988. 

As the forest in this planting evolved, a number of trees were removed after some trees couldn’t keep up with the competition for light – a common phenomenon in natural forests. The composition was rearranged to ensure the longevity of the planting.

The photo above is how the planting appears at the Museum today. The large pond cypress on the left with a strong lean provides directionality, while the group of bald cypresses on the right provides depth. The seven-foot stone slab, which weighs about 1,500 pounds, evokes a natural look compared to the typical ceramic container. 

Come and visit The National Bonsai & Penjing Museum in all four seasons to experience the beauty of Taxodium in the collection. The lush bright green spring growth and the brilliant red and orange fall foliage is best to appreciate in person. I hope that these trees inspire everyone to work more with native species and create bonsai in a meaningful manner.

Species Spotlight: Japanese Black Pines (Pinus thunbergii)

Enjoy this new blog column, Species Spotlight, from our First Curator’s Assistant, Andy Bello. Be sure to check out more from Andy on our blog with his Historical Tree Spotlights.

Japanese Black Pines growing on rocks in a coastal environment (https://www.chushikokuandtokyo.org/spot_52/)

Japanese black pines (P. thunbergii) are native to the coastal areas of Japan and South Korea, from sea level to about 3,000 feet of elevation. The trees prefer warm moist climates, where they rarely suffer frost. In Japan, the pine has been highly valued for centuries as an ornamental feature in Japanese-style gardens and for bonsai. Japanese black pines are hardy to U.S. Department of Agriculture Zone 6, but the trees can be kept in colder conditions if proper winter protection is provided.

The National Bonsai and Penjing Museum is a wonderful location to experience Japanese black pines as bonsai and penjing. This species is widely used across the world as artistically-trained potted trees, and the many different shapes these trees take are influenced by cultural and personal experiences. Here we will examine and discuss three Japanese black pines that are on display in the Japanese, North American and Chinese collections.

This first Japanese black pine, displayed in the Japanese Pavilion, was part of the original Bicentennial gift to the American people in 1976.  Donated by Goro Ito and in training since 1906, this tree was collected from the wild on the Atsumi Peninsula, located in the Aichi Prefecture. The pine is a beautiful representation of the coastal environment of its origin, mixed with the traditional Japanese bonsai form. Coastal trees tend to flaunt wider upper canopies than trees growing in alpine environments where snow accumulation on branches creates a more narrow, conical form.  

This bonsai’s curved trunk suggests an aged tree that has survived strong coastal winds and typhoons. The asymmetrical triangular form of the foliage mass demonstrates the traditional Japanese bonsai style.

The next Japanese black pine is located in the North American Collection and was donated by George Yamaguchi in 1990. Yamaguchi grew this tree from a seed and has been training the pine since 1955. It is styled as a formal upright bonsai and is known by the name “Shinsei,” meaning “Voice of the Gods.” To me, this tree represents a lone pine growing in a meadow at higher elevation. The strong and numerous branches lower on the trunk indicates that the tree had little to no competition from other trees, in contrast to a pine growing in a forest where lower branches are lost due to lack of light. The overall conical shape of the branches suggests a tree subjected to snowfall at higher elevations.  

This particular tree is a great example of the influence of Japanese bonsai style in North America. The lower right branch establishes the tree’s asymmetrical form, and the foliage pads on each branch are distinctly separated. North American bonsai, very similar to North American culture, are extremely diverse. Thanks to this diversity, there is no right or wrong way to represent the form of a tree in miniature. 

Dr. Yee-sun Wu donated this Japanese black pine, now part of the Chinese Collection, in 1986. The pine has been in training since 1936, but the tree’s origin is unknown. This tree’s style differs greatly from our previously discussed trees. The dramatic movement in the trunk line guides the viewer's eyes up into the foliage mass. The long primary branch, a feature of the “Lingnan” style of penjing common in Southern China, extends dramatically to the right, presenting a strong sense of movement. Penjing, especially in the case of this tree, tend to be more whimsical in their form than Japanese bonsai. The foliage pads are still present but typically are not as “clean cut” as foliage pads on Japanese bonsai. 

Penjing can take many forms other than simply a miniature tree – the trees can be shaped into animal forms, cylygrophy, landscapes and more. For more on penjing, read our interview with bonsai master Qingquan Zhao. 

FIRST CURATOR'S BLOG: My First Six Months as a Curator’s Apprentice

As we crawl toward the end of the summer and into the beginning of fall, I look back on my first day at The National Bonsai & Penjing Museum in March. They say, “Time flies when you are having fun,” and I very much agree. Caring for and working on bonsai full-time for the past six months has been even more amazing than I could have imagined. Since my first day, I have met many talented and friendly bonsai artists from around the world, from whom I have learned specific design and horticulture techniques for various species.

Andy Bello with Michael Hagedorn on World Bonsai Day 2019 at the National Bonsai & Penjing Museum

I took some time off and traveled to Bremerton, Washington, where I had the privilege of staying and working with Dan Robinson – a seasoned bonsai professional – for a little over a week. I also visited with Aaron Packard, the curator of the Pacific Bonsai Museum and former assistant curator of The National Bonsai & Penjing Museum. I learned and shared ideas about bonsai with artists who influence my personal work. I experienced and gathered inspiration from the wonderful ancient trees that still exist in the Northwestern United States. 

Bello prunes a Korean black pine with a nice view at Elandan Gardens in Bremerton, WA

Working on the trees in the National Collection has been an extremely educational and enjoyable experience. I have worked on a diverse collection of species, while also learning when and how to apply different techniques, including when are the best times to prune, wire, fertilize and repot, depending on the season. My favorite seasonal tasks thus far are repotting in the late winter and early spring or decandling or removing spring growth from red or black pines to stimulate a second flush of growth in the summer.

Working on trees donated by prominent figures in bonsai history – including John Naka, Saichi Suzuki and Bill Valavanis – has been a humbling experience.

Post decandling on Japanese black pine (Pinus thunbergii) donated by Saichi Suzuki

Thinning and structural pruning on the “Yamaki” white pine (Pinus parviflora)

As I move into the second half of my apprenticeship, I hope I can continue to meet and befriend other bonsai artists and enthusiasts and continue to expand my horticulture and design skills. I will continue to share the wonder and joy of bonsai with the public who come to visit The National Bonsai & Penjing Museum.

Best,

Andy Bello

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Andy Bello has been selected as the Museum’s 2019 First Curator’s Apprentice.  The National Bonsai & Penjing Museum's First Curator's Apprenticeship  for 2019 is funded by generous grants to the National Bonsai Foundation from Toyota North America and The Hill Foundation. More on Andy here.

FIRST CURATOR'S BLOG: Stories of Struggle and Survival

When viewing old and ancient trees – whether they grow in a city, forest, desert or alpine slopes – one comes across stories of struggle and resilience. These stories are depicted in many ways depending on the species of tree, the characteristics of its wood and the environmental event that caused damage to the tree. 

Deadwood on bonsai is generally spoken about using the Japanese words “Jin,” meaning dead branch, and “Shari,” meaning deadwood on the trunk.

Damage that results in the contortion of a tree can occur in bouts of extreme weather, like heavy snow, droughts, wind, lightning and more. Biological damage – events like animals grazing, insect infestations and human activities – also affect the contortion of a tree. 

All these impacts occur throughout the life of trees, sometimes over the course of thousands of years, like the ancient bristlecone pines in the White Mountains of California which have been dated to about 6,000 years old.

After the damage occurs, deadwood features can take on many different appearances, depending on the species and environmental conditions that the tree resides in. 

In wet climates, many deciduous species with softer wood may form large hollows due to rotting and decay. But the deadwood on many junipers in dry climates will be sun bleached white by the sun, resulting in a look that is naturally preserved for longer periods of time. 

In bonsai design, deadwood adds interest and a “survival story.” Sometimes an artist might collect a tree that already has naturally occurring deadwood. But artists can also create deadwood by breaking branches, stripping away bark and carving wood using hand or power tools. 

Artists generally treat deadwood on bonsai with a solution of lime sulphur. This solution protects it from rotting and bleaches the deadwood, giving it a white appearance that contrasts well with the rest of the tree. Penetrating wood hardeners can also be used on the deadwood if a bleaching effect is not desired.

Each bonsai artist can decide whether to create deadwood on all trees or leave the variation to certain species. The real beauty of bonsai is not whether the tree has deadwood features, but is demonstrated in each person's ability to create and share their view of nature from their own life experiences. Bonsai is an art, and with any art there is no right or wrong.

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Andy Bello (Stephen Voss)

Andy Bello has been selected as the Museum’s 2019 First Curator’s Apprentice. The National Bonsai & Penjing Museum's First Curator's Apprenticeship for 2019 is funded by generous grants to the National Bonsai Foundation from Toyota North America and The Hill Foundation. More on Andy here.

Museum Appoints Andy Bello as Curation Intern

Andy Bello, the National Bonsai & Penjing Museum’s 2019 First Curator’s Apprentice. (Stephen Voss)

Andy Bello has been selected as the Museum’s 2019 First Curator’s Apprentice.  The National Bonsai & Penjing Museum's First Curator's Apprenticeship  for 2019 is funded by generous grants to the National Bonsai Foundation from Toyota North America and The Hill Foundation.

Bello, a 24-year-old Illinois native, earned a Bachelor of Science in Natural Resources Conservation and Management from the University of Arizona in 2016. He then moved to Eugene, Oregon where he designed and built ornamental ponds, propagated pond plants and bred koi and goldfish at a local store.

His fascination with bonsai catalyzed after he stumbled across Peter Chan’s “Bonsai: The Art of Growing and Keeping Miniature Trees” in 2016.

“I took this book home, and the second I opened it I could not put it down,” Bello said. “Everything from the history of the art, the horticulture aspects, and the design techniques amazed and intrigued me deeply.”

His readings prompted him to join the Eugene Bonsai Society, a group of Oregon bonsai enthusiasts. Bello said he felt welcome in the society, but after spending a year in the group he wanted to delve deeper into the bonsai realm and craved hands-on experience.

His big break occurred on a trip to the Oregon Coast, when he inadvertently stopped at Driftwood Nursery in Bandon, Oregon. Bello befriended nursery owner Tom Roberts and soon began a monthly apprenticeship at Driftwood, where he learned basic bonsai skills and developed his passion for the trees.

Bello said he and his girlfriend soon began to discuss moving east to solidify their careers and settle down close to family. In preparation, he explored available permaculture and organic farming jobs on the East Coast – eventually discovering the Museum’s curator apprenticeship – and immediately sent in his application.

In his newly-appointed position, Bello aims to deepen his understanding of different species’ needs in all seasons, and looks forward to improving his horticulture skills and bonsai designs.

His year-long internship will consist of performing various bonsai care-taking duties, from repotting and wiring to pruning, and spreading the joy and wonder of bonsai to Museum visitors.

“I am extremely excited to be part of a new community of fellow bonsai artists and create new connections from all different parts of the world,” he said. “I hope to learn and grow as much as possible in the world of bonsai.”

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The National Bonsai & Penjing Museum's First Curator's Apprenticeship for 2019 is funded by generous grants to the National Bonsai Foundation from Toyota North America and The Hill Foundation. If you’d like to help fund these types of programs, please consider becoming a member of the National Bonsai Foundation. More information here.