John Naka’s California Juniper “Heisei”
By George Haas
February 8, 2025

Bonsai Garden at Lake Merritt (BGLM) Item #146 California Juniper (Juniperus californica)

Donated by John Naka on October 26, 1999.

History: This tree was collected by John Naka on November 29, 1989, from the northwest end of the California Mojave Desert referred to as the Sand Canyon. Permission to dig the California juniper was given by the Quail Mountain Ranch in Sand Canyon.

Named “Heisei” which means achieving peace and harmony in Japanese. The name was given by John Naka because the tree was collected in 1989 and it was also the year the new Emperor of Japan named the era Heisei.

“Heisei Bonsai” refers to a style or approach to creating bonsai trees that developed during the Heisei era in Japan (1989-2019). Bonsai is the Japanese art of growing and training miniature trees in containers, and it has a rich history and various styles, such as formal upright, informal upright, slanting, cascade, and forest.

The Heisei era brought about innovations and a modern sensibility to the traditional art of bonsai. Some Heisei bonsai artists have been known to experiment with new techniques, aesthetics, and species of trees, while still respecting the core principles of this ancient practice.

Who was John Naka?

John Yoshio Naka (August 16, 1914 – May 19, 2004) was an American horticulturist, teacher, author, and master bonsai cultivator. Author of Bonsai Techniques I and Bonsai Techniques II, texts that are revered as being the bibles of western bonsai to many artists.

Awards and honors.

On May 23, 1960, an honorary citation from Japan’s Minister for Foreign Affairs Shunichiro Fujiyama for effort in promotion of goodwill and friendship between Japan and the United States.

On November 24, 1967, an honorary medal and citation from the President of Japanese Agricultural Affairs Department, Prince Takamatsu and Eikichi Hiratsuka.

On May 20, 1972, an honorary citation from County of Los Angeles’ Supervisor Ernest E. Debs on behalf of the County for his outstanding contributions to the Japanese American friendship by providing the people of Los Angeles and the nation with ability to understand and appreciate the beauty and significance of bonsai culture.

In 1985, Emperor Hirohito of Japan bestowed upon John Naka the most prestigious award for a non-Japanese citizen, The Fifth Class of the Order of the Rising Sun.

In 1990, the North American Pavilion at the National Bonsai & Penjing Museum, on the grounds of the United States National Arboretum, was named in honor of John Naka. His famous bonsai “Goshin” is displayed at the entrance. In 2001, a portrait bust by Bonnie Kobert-Harrison was unveiled there.

Naka was chosen in 1992 as one of thirteen honorees to receive a National Heritage Fellowship, the first bonsai artist to receive this prestigious award.
He was awarded a 2009 Pacific Pioneer Award posthumously. The American Bonsai Society named the John Naka Award for him. An endowment fund was established in his name.

In May 2014, Naka became the first inductee into the National Bonsai & Penjing Museum’s Bonsai Hall of Fame.
John Naka is referred to as the father of North American bonsai for his efforts to promote the living art of bonsai throughout the U.S. and world. He was present and spoke at the grand opening of the Bonsai Garden at Lake Merritt in Oakland, California, on November 6, 1999.
Repotting of “Heisei”.

BGLM volunteers Samuel Tan and Addison Galambos undertook the task of re-styling this iconic bonsai starting on January 28, 2024. Upon completion of the re-styling, the tree was displayed on wooden blocks and angled to show its new position when repotted later. The tree was allowed to gain foliage and overall strength before its repotting.

On February 8, 2025, Samuel Tan and Addison Galambos led a team of volunteers in the repotting of the California juniper. Other volunteer team members included Yuri Aono, Michal Tiede, Nicole Yabut, Nick Vila, Brett Witmer, Alexander Dulkin, and Paul Jones.

A general rule for repotting a large bonsai tree would be five to seven years due to the following factors:
o Age of the tree
o Size of the tree and pot
o Breakdown of the soil or compacted soil
o Root growth or root bound
o Water flow decreases

The last time this California juniper was re-potted was on February 8, 2021.

 

Repotting Workshop for the Bonsai Garden at Lake Merritt
By George Haas

On January 21, 2025, from 9:30 a.m. to 2:45 p.m., at the Bonsai Garden at Lake Merritt (BGLM), a bonsai repotting workshop was led by professional artist and instructor Adam Toth for BGLM volunteers, also referred to associate curators who work on the collection trees.
The repotting workshop was open to all skill level bonsai practitioners. This was an opportunity for BGLM volunteers to learn the latest bonsai repotting techniques from Adam who studied as an apprentice in Japan.

Similar workshops will be scheduled for working on collection trees during the year.

All bonsai require repotting from time to time. General rules for repotting bonsai trees are one to two years for small, three to five years for medium and five to seven years for large. However, repotting intervals may vary due to the following factors:

Age of the tree
Size of the tree and pot
Breakdown of the soil or compacted soil
Root growth or root bound
Water flow decreases

Repotting may require a variety of hand tools:

o Wire cutters
o Pilers
o Large root scissors
o Root cutters
o Rubber mallet
o Tweezers
o Chopsticks
o Steel pick
o Single prong root hook
o Triple prong root hook
o Japanese large sickle saw
o Japanese small sickle saw
o Repotting blade
o Soil tamper
o Whisk broom
o Plastic drainage mesh
o Aluminum wire

Adam started by pairing volunteers to work as partners on the repotting of collection trees. For this workshop session, a total of ten BGLM volunteers participated.

Various trees were selected from the collection to be repotted, both conifers and deciduous. The paired volunteers worked as teams to repot the trees, all of which were due based on the aforementioned repotting factors.

Most trees were repotted into to the same pots. In some instances, the teams selected different pots which may have been larger or deeper. Pot selections were due to evaluations of the tree’s health or root mass and condition since last repotting.

Generally, the procedures for repotting bonsai trees are the same. Start with removing the tie down wires cutting from the bottom of the pot. Use a Japanese sickle saw or blade to remove soil from the inside edge of pot. Adam showed how to hold and angle the saw so that soil is moved to the inside, using a scrapping motion and increasing the depth of the saw with each pass.

Removing the bonsai tree should be removed from the pot with ease. Although, a rubber mallet can be used to tap the rim of the pot, if needed. It works well with one holding the bonsai tree and pot and the other removing the entire tree.

The pot is then thoroughly washed and cleaned with a brush and water. The pot should be prepared to receive the bonsai tree by installing plastic drainage mesh and tie down wires. A single layer of pumice or soil mix is placed in the bottom of the pot with a mound built in the center. The pot is then set aside, and work is begun on the root ball.

Adam demonstrated starting at the bottom of the root ball by removing up to a third of the roots and old soil. A Japanese sickle saw is useful for this work. The loosened roots are then cut with a sharp root scissors, making sure the bottom surface is flat. Nest, the roots at the surface and sides are worked by raking with a prong root hook. Combing the roots away from the trunk and trimming the sides with root scissors.

Note that on confiers, the root ball may be dense and compacted so that water will not penetrate it, as needed. In this case, use a steel pick to make a number of holes in the root ball so that water will be able to penetrate its core.

The bonsai tree is ready to be placed into the pot. Take the time to adjust the front and sides of the bonsai tree and make it centered in the pot or as desired. Press the root ball and move it side to side to settle the root ball within the mound of soil previously placed in the pot. Add some more soil to the sides of the root ball and then secure the tie down wires to ensure there is no movement of the root ball.

Add more soil to the pot and begin to remove air pockets by using chopsticks. Adam showed the technique for using chopsticks to remove air pockets. It requires sliding the chopstick down the inside edge all the way to the bottom of the pot. Then raise the chopstick and observe the soil level to move lower to fill the air pockets. Level the soil slightly below the edge of the pot rim and proceed to press down on the surface using a soil tamper.

When the repotting is complete, it is critical to thoroughly water the bonsai tree. Light sprays of water will flush out any fines making the cloudy water turn clear.