36th Annual Show

The 36th Annual Show by the Redwood Empire Bonsai Society (REBS) was held on August 24 and 25, 2019 at the Santa Rosa Veterans Memorial Building, Santa Rosa, California. The REBS annual show is the largest club show in the US. Some 200 bonsai were on display. The San Francisco Suiseki Kai joined again this year to show their suiseki viewing stones. Visitors were treated to two rows of tables with viewing stones from northern California and Japan.

Club sensei Kathy Shaner oversaw the placement of bonsai, companion plants and art objects. She conducted a demonstration, both days, working on a Sierra juniper and Coast redwood, respectively.

A special thank you to the club members who contributed to the annual event by displaying their bonsai and helping to set up, docent and clean up.

Here are some of the outstanding bonsai featured in the annual show.

Enmanji BBQ Annual Bonsai Display

On July 14, 2019 (the second Sunday of the month), it was time for the Enmanji BBQ annual bonsai display by the Redwood Empire Bonsai Society (REBS). Art Kopecky chaired the event by recruiting other REBS members to display their bonsai. A special memorial tribute was given to Ian Price of Lone Pine Gardens, Sebastopol, California. Ian was one of the founding members and a charter member of REBS.

Demonstration by Bill Castellon – Princess Persimmon

On June 25, 2019, Bill Castellon performed a demonstration on a Princess Persimmon. Bill brought to the monthly meeting and demonstration several personal specimen bonsai of the Princess Persimmon. He also brought several Princess Persimmon trees to work on as demo trees and to be raffled off at the conclusion of his demo. Bill favored the Princess Persimmon for its tiny bright orange to red fruit, small diamond shape leaves and ease of propagation. Bill said the demo species are not readily available nor inexpensive. He said that the species in California were mostly from a group of 2,000 plants imported years ago by Carl Young of Lodi, California.

Princess Persimmon (Diospyros rhombifolia) is dioecious, that is separate male and female plants are required to produce fruit. It is a deciduous tree, originally from China and secondary Japan. It is popular for bonsai due the size of the tree and small fruit.

Bill described his experience and success with propagation of the species by root cuttings. He said root cuttings will produce or replicate that of the parent tree. This is not so with the seeds which can produce variations in the fruit.

The fruit ripen at varying times and so it can be difficult to prepare for a display. The fruit forms on the new growth each year. Pruning can be hard after the fruiting is over. The tree grows quickly. Bill applies fertilizer on a regular basis. He uses Romeo products out of Half Moon Bay, California. He uses the general purpose 15-30-15 fertilizer. Romeo products can be found at a number of retail stores and nurseries in the San Francisco/Bay Area. He feeds fertilizer all summer.

Bill used a bonsai soil mix of Akadama, lava rock and perlite or pumice. His preferred portions are 60% Akadama, 30% lava rock and 10% perlite.

Pests and diseases: Bill recommended three doses of a fungicide for the winter months.

Bill started his demo on the largest of three trees. First, he eliminated one side of a bar branch. He used a sharp knife to clean the wound, a common task for deciduous trees. Cut paste applied over the cleaned wound. He then removed any dead branches and unwanted branches. Aluminum wire was used to wire various branches. The branches can be brittle and so wiring must be carefully wrapped around the branches using both hands; left hand to guide the wire in place and right hand for wrapping the wire around the branch. That is if you are right handed, of course.

Bill described the technique for creating ramification in deciduous trees by allowing some branches to grow outward as long as needed to gain the strength and thickness desired, and then cut back to the secondary branches. Bill kept the demo tree tall and slender with slight movements in the wired branches.

Watering: Bill said he will allow the tree to be on the dry side before watering. Do not let the tree dry out completely.

As with many of the deciduous bonsai, morning sun and afternoon shade seems to work best.

Bill offered the demo female tree with a companion male tree as one of the evening’s raffle prizes. Another female semi-cascade tree was also offered for raffle.

Bill’s Princess Persimmon at GSBF Convention Exhibit 2018
Bill’s Princess Persimmon at Demo June 25, 2019

Demo Princess Persimmon tree.

Oak Styling and Development

There are many ways that oaks adapt to the landscape but the form most associated with oaks that grow on the rolling hillsides and open areas of the landscape is embodied by rounded foliage silhouettes grounded by a buttressing trunk that splits into several vertical and slanting leaders. These trunks, in turn, meander up and around, casting branches every which way to form sub-crowns in the informal umbrella­like shape. Oaks are usually broader than they are tall and are marked with a fountain­like upward and outward branching theme with the tips drooping slightly at the exterior edges.

Unlike pines which are typically styled with defined branches and pads, oak branching takes off more randomly with riotous. Heavy interior branch movement, eventually reducing down to fine twigs at the edges of the silhouette.

The beautiful movement in a mature tree in the landscape is a result of years and years of multiple shoots extending, competing for sun, crowding out weaker shoots, being damaged in windstorms and by insects, wildlife or pathogens. Some just die out and others fill the void in the canopy vacated by those dead shoots and branches.

All of those shoots start out straight. It is the incremental nature of growth over time that yields the wild curves in trunk and branch. In Bonsai, we try to compress those years of movement by wiring those straight shoots with exaggerated curves. When wiring a bonsai branch, the most important section is the first three to five inches. Growth longer than that can be allowed to grow straight to thicken up the interior curves and help them set faster. Bending creates a succession of arcs from which the next shoots will come. This series of arcs, as opposed to straight lines, creates a more natural feel to the tree.

Bonsai Training

As much as possible, working with new shoots yields the best results. They can be manipulated freely without having to fight an old leggy branch with dead patches and aging, reluctant latent buds. Young shoots and branches devote most of their energy to growth and expansion. Older branches lack the same dynamic energy for growth as they must allocate resources to maintain heartwood, sapwood and dead stretches due to shari and jin.

For an oak, the phyllotaxy, or the arrangement of leaves on a shoot, is five to two. This means that between one leaf and the next one in the same position on the shoot there are five intervening leaves rotating twice around the shoot at about 144° between leaves.

Trivia? Yes. When we bend curves in the oak shoot, we can use this growing feature to add randomness to the branch angles and get that meandering oak characteristic.

After allowing the fall growth to mature and store energy in the vascular system of the tree over winter, the tree can be cut back hard in mid-January on both deciduous and evergreen oaks to the point where new shoots are desired. Sometimes, even on an evergreen that means going back to bare wood, leaving no green growth left on the branch. Scary stuff! But forge on! Remember to seal the large cuts with cut paste. To develop branches from scratch on evergreen oaks, try the following procedure.

Year 1. After the above cut back in January, new shoots pop on native oaks at and just behind the cut appearing in late February-early March as the days lengthen and it begins to warm up. New growth is allowed to harden (they become less succulent, turn darker in color and get stiffer, waxier leaves) usually by mid to late April. (Cork oaks are usually about four to five weeks later). New shoots are wired out four to five inches or so in an inclining slope, bending the shoot mostly up and out and up and out, then a little side to side movement in this same section. The shoot tips should be allowed to grow unrestricted for the remainder of the year but remember to remove the wire when it starts biting in, usually in six to eight weeks.

Year 2. Next January cut-back, leaving three to four inches of the new curved branch area. Repeat last year’s process; cut, harden, wire, remove wire, grow. But this time there may be lots of shoots on the three to four inches. Wire three of the shoots (backside, front side, and top) in the same manner as Year 1.

Year 3. Next January, the three secondary shoots from last year are each cut to two to three inches, wired in April after hardening, then choose six shoots (two on each of the three shoots from last year) to wire. Again, remove the wire after the bends are set and, at this time, cut back each of the six shaped shoots to two to three inches. When new shoots come out and harden, wire two shoots and let the branch set in position yielding 12 tertiary shoots. Remove the wire when the bends are set and leave until next January’s cut-back.

Year 4+. From then on refine the branches by cutting back to two to three leaves in January, and each time there-after, as the shoot elongates and before it hardens, leaving a side shoot and leader. Wiring and big cuts won’t be required other than to occasionally adjust the styling or thin over crowded areas. By now, the branch will be well on the path to having that nice ramified oak appearance with good transitional taper.

Defoliation every year or two, can help reduce leaf size after growth hardens, up to about August 1st. Be cautious thereafter. Only defoliate on healthy trees!!

Occasionally, allow a random interior branch to grow outside the canopy without wiring. When it gets past the established silhouette, strip the leaves up to that silhouette and allow it to then run unobstructed. This sacrifice branch will give better transitional taper for the tree where needed, as well as create mature bark, especially with cork oaks. Young, rampant growth is the key to getting good bark. Eliminate the branch when it has accomplished its job and before it weakens the area around it.

We want those interior branches to remain strong because, no matter what we do, the tree will eventually expand and become leggy. Then we need those branches to cut back to and restart the building process. Who said that Bonsai is not perpetual fun?

Ramification maintenance. When the desired branch shape is achieved, pinch back the extending shoots, as they open, at the edges of the branch silhouette. Allow shoots to fully extend if you need to fill a hole in the branch shape.

Deciduous oaks can be cut back in January and thereafter to two to three leaves in May after hardening and maybe once again if it’s extremely strong. Total defoliation of deciduous oaks late in the year (August forward) is very risky and hard on them, using up a lot of the energy reserves of the tree. They can sometimes shut down and wait until the following year to produce new shoots, or throw out a few shoots while cutting off and killing some branches you need. However, after leaf hardening, early defoliation thru June will reduce leaf size and if paired with cutback can generate new shoots as well. If you can’t defoliate, cutting back and thinning the upper section of each branch crown will allow light below, will save interior leaves from dropping and shoots from weakening. Keeping them super healthy and active is important.

Tree Stage

Bonsai Care and Development

Operations and Purpose


Trunk Development Primary Branches

Secondary I Tertiary Branches Twigs and Foliage Maintenance

(Revert back to earlier stage when necessary to solve problems)

Whole Tree

  1. Sun I Temp I Wind – adjust growth cycle – damage control
  • Water – maintain proper hydration
  • Soil I Pot- size and composition / volume and shape
  • Transplant interval – speed-up / slow down growth – refresh
  • Fertilizer- growth regulation – amending for health
  • Pest Control – treat and/or get ahead of Insect and fungus

Targeted Operation

  • Cutting Branches or Leaves Pinching- shorten internodes – maintain shape – bifurcate Pruning – determining shape – bifurcate

Thinning – Open cramped areas – save inner branches

Defoliation – reduce leaf size

  • Wiring – Shape Branch / Design

Dec. 21 Winter Solstice

Mar. 21 Vernal Equinox

June 21 Summer Solstice

Sep. 21 Autumnal Equinox

Angle/ Intensity of Sun Temp

Perform Operations at the Appropriate Times in the Plant’s Growth Cycle

Hormones Auxin · Apical Growth

Cytokinin – Lateral Growth

Pinch/ Prune Hint

“rule” of 2 –Leave 2 buds / leaves – a leader and a side shoot

Wiring Hint

Bend in toward main, then bend out toward sun.

This handout was prepared by John Thompson (2019)