On February 25, 2020, at the Luther Burbank Art and Garden Center, Santa Rosa, California, Jonas Dupuich was the guest bonsai artist and instructor for the members of Redwood Empire Bonsai Society (REBS). Jonas demonstrated on creating and growing exposed root Japanese Black Pine bonsai. He has been growing Japanese Black Pine from seeds for the past 26 years. The exposed root bonsai technique is most popular with the Japanese dwarf flowering quince or Chojubai bonsai. It is used with Japanese Black Pine and Satsuki Azalea bonsai as well.
Jonas brought to the demonstration two of his own examples of mature exposed root Japanese Black Pine bonsai. Each 16 years in training, grown from seed. See photos.
In addition, he also brought Japanese Black Pine exposed root plants, one 10 years in training and the other one-year old, both from seed. These two plants were raffled upon completion of the demonstration. See photos.
Style – exposed root bonsai can be given the story as falling off the side of a cliff or even damaged from a flooding. It can be with long versus short roots depending on design. The roots may be thick and large or slim and small. There can be a certain balance of roots supporting the trunk.
Pots – suitable pots are usually round in shape and can be grey, red or brown.
Jonas began his demonstration with a slideshow depicting various exposed root Japanese Black Pine bonsai from a recent trip to the Kokufu Ten 2020 Exhibition and Green Room in Japan. The pictures showed different shapes and paths for the exposed roots. No one bonsai looked the same.
The first demonstration plant was the one-year old. Jonas used a one gallon nursery container and blocked the large holes in the bottom with construction sheet wall tape to prevent soil from leaking out. He then filled the bottom with a small bonsai soil mix (Clay King premix and pumice). Next, he inserted larger pieces of Japanese Hyuga (pumice). Jonas used a long nursery container popular with nurseries for Blueberry plants and placed it upside down (narrow bottom with a hole on the up side) in the one gallon container. By placing the second container upside down this would prevent the roots from growing wide to narrow or like a reverse taper. This second container was then filled with the Hyuga large pieces. Finally, the one year old Japanese Black Pine plant was inserted through the hole with all its roots attached. With the roots planted in the second container, it is then filled with more of the small bonsai soil mix. The latter will help keep the roots moist.
Jonas commented on watering by citing less water was needed. It should never be allowed to dry out completely.
Jonas said the planting should be checked three to five years later unless you want a smaller exposed root bonsai, like a Shohin. Once you established the size of the roots desired, then you must remove the small bonsai soil mix and large pieces of Hyuga. This is best done with a pick tool or chopsticks.
The exposed roots can be then manipulated in many ways to style your bonsai.
Jonas moved on to the 10-year old exposed root Japanese Black Pine demonstration tree. This plant was contained in a round terra cotta pot with the exposed roots partially planted inside plastic bonsai drainage screen material. The plant was allowed to grow without much attention. There were two large sacrifice branches for thickening the trunk still attached. A number of smaller branches were located near the base of the trunk.
Jonas first wanted to choose a front view and there were two options based on the shape and flow of the existing branches. The front view was marked with a chopstick. Of the smaller branches, two long branches near the base of the trunk were selected to wire. A single piece of Aluminum wire was used to wrap around the two branches. Starting at the back, Jonas wrapped the wire around the two long branches. He cut off several of the smallest branches as they were not needed. Once wiring was done, Jonas had REBS member Diane Matzen to establish movement in a downward direction and end facing the front view. Then, on the other wired branch REBS member Michael Murtaugh established movement in an upward direction, ending towards the front view. These wired branches gave the future owner choices in styling the bonsai, either downward for a cascade or upward for an informal upright style.
Jonas discussed the technique of bending branches and putting movement in the bonsai. He said bending should always start at the trunk and move in a downward or upward direction. There should be no flat wiring or straight areas. Always check your bending of branches afterwards and fix any straight areas. Black pine branches are very flexible but always support with your fingers the bends.
Upon completion of the demonstration, Diane Matzen won the 10-year old bonsai and REBS member Mike Nelson won the one-year old bonsai. Congratulations to both.