Marin Bonsai Club

John Thompson, an arborist, bonsai enthusiast, and oak specialist who has worked with trees since the ’80s, gave the Marin Bonsai Club its first oak demonstration in eight years this October, and it was well worth the wait.

John was kind enough to provide everybody in the audience with a cardstock copy of what he calls his “Toolbox,” a copy of which is included here. John said he has developed this “cheat-sheet” of sorts throughout his time as a bonsai enthusiast and always refers back to it when in doubt regarding what needs to be done next with a particular tree. He invites and encourages us to do the same. Much of what is there will be familiar to anyone who has attended past Marin Bonsai lectures by Peter Tea or Jonas Dupuich. As John proceeded, he loosely followed the outline of his Toolbox.

As he began to thin branches on the demo tree, John pointed out more of the features of his Toolbox handout. The far right of the handout outlines important dates for timing various types of tree work, including some general reminders about pinching and wiring. The middle part of the handout covers all the different types of tree manipulations, the part that is most like Peter Tea’s keystone summary of the different types of manipulation. John nicely divides them into those methods that affect the whole tree and those we use to work on specific, targeted areas.

While introducing two of the three trees he brought, all valley oaks, John talked a bit about all the different varieties of oak available in California and some of the ways oaks are unique. He pointed out that while conifer branches initially tend to point downward and deciduous branches tend to point upward, oaks are different because their branches can go all over, as anyone who has driven on Highway 101 between Novato and Petaluma knows. Oaks also tend to be wider than they are tall. All these factors must be considered to produce a realistic likeness in an oak bonsai.

An interesting side note John made involved collecting cork bark oaks (one of his favorites!) from wine vintners, who use them to make . . . you guessed it, corks. John emphasized how important it is to get trees that have been discarded in their first ten years of life. That’s because the vintners like their bark straight and less gnarled by branch growth and such. To get them that way, they strip all the original bark and lower branches after ten years of growth, so that what grows back is less gnarled and more conducive to compact, straight-grained corks. Definitely not a good look for bonsai, though!

The third tree John brought with him was the demo tree, one he purchased from a Calaveras nursery almost a year prior. He put its age at about 8 to 9 years old. As he began to assess the tree to determine where to start working on it, he drew our attention to the top left side of his Toolbox handout, where it outlines the stages of work that can be done to a tree. Peter Tea fans will recognize the priority: The trunk is always considered first. Only once that is close to where it needs to be can we start thinking about how to make the primary branches better, then secondary branches, and so forth. Failing to follow this priority can lead to wasted work done prematurely on areas that will end up having to be chopped off to correct a higher priority area. John already knew that the tree had a good trunk, that’s why he chose it, so he proceeded to choose the primary branches so he could begin to thin the others away. He also acknowledged that we need to choose a front for the tree, but moved on without involving the audience in that decision.

As his work on the demo tree progressed, John continued to give general bonsai and specific oak tips. He said that knowing your tree type is important for knowing what you can do to it. Not just knowing things like the fact that deciduous trees are hardwood and cannot be bent as easily as conifers, like pines and junipers. You also should try to get to know the specific characteristics of the species you’re working on so that you can emulate them in your design, like the fact that the interior growth areas of white oaks tend to be bare.

While assessing the demo tree and contemplating what to do with the bushy top, John reiterated a point we have learned many times over from Peter Tea, which is that balancing the energy of a bonsai often means close-cropping the top and letting the bottom branches go for awhile. As a counterpoint, he also pointed out that in nature, older deciduous and evergreen trees are more rounded on top, whereas younger trees are pointier, so to depict age in our bonsai, we should develop a full canopy. Choosing the correct approach for the demo tree proved a little tricky, since its canopy was somewhat divided into a few separate rounded crowns. Rather than sacrifice any of the tops, John decided to trim a little heavier (creating shorter branches) between the different crowned sections, to help differentiate them. That would allow the winner of the tree to develop all of those tops, either for later selection of the apex, or to induce ramification in order to combine all the tops into one canopy, all while satisfying the need to encourage energy redistribution to the lower parts of the tree.

So John trimmed the multiple crowns pretty short, to keep them suppressed. While doing that, he reminded us to cut back shorter than what we actually want when doing major pruning, to leave room for branch division and ramification out to the point where we want our final tree outline to be. In the end, the demo tree was encouraged to grow outward more, upward less. Not too much was trimmed off, so this tree could be repotted this coming spring. John finished with a quick description of how that process should proceed for an oak recently purchased from a nursery. He said he usually begins by chopping off the bottom half of the existing nursery soil. Then, next repotting, only replace half of the soil, horizontally. Two years later, clear and replace the other half, similar to how we repot pines.

The demo tree was won by Chris Ross, who promised to show us the tree’s progress at later club meetings.

– David Eichhorn

Marin Bonsai Club and guests were treated to an educational and entertaining presentation on bonsai rock planting by Jay McDonald at the September 2019 meeting. In the Japanese tradition this is called a saikei (sigh-kay) and in the Chinese tradition penjing. The volcanic stone Jay used had a dramatic arched shape and he chose a small, shohin-sized shimpaku juniper for the signature planting. Jay discussed the various positions he had considered for positioning the tree before deciding that a placement just off center showed the tree to the best advantage and flowed well with the lines of the stone.

Ever considerate of his audience’s limited attention span, Jay had done extensive preparation on the stone and tree before the meeting. Screen platforms or pockets for soil were created to provide growing material and stability for the tree, and drainage holes created to keep the roots healthy. Jay had purchased the tree in August, pruned and styled the branches and cleared the roots of old soil so it would be in prime condition for planting on the stone.

It was clear that Jay had done considerable thinking about his composition and the elements needed to create a composition that would be a real show stopper. He had purchased several accent plants that mimic larger plantings one might see in the woods, and had accumulated some prize silverback moss to fill in and secure some of the plants.

Peter Tea joined us in August to talk about the work that is appropriate to do on junipers late in the summer. He brought three Kishu Shimpaku junipers with him, plus an olive for contrast, and to illustrate how different trees need different approaches.

Peter began with a quick recap of the importance of working on healthy trees, listing once again the six things we can manipulate to ensure that we get the most out of our trees and the changes we make to them: sun, water, soil, repot interval, fertilizer, and cutting.

The Kishu Shimpaku is, like most junipers, highly valued for how great it looks with foliage pads, those perfectly shaped bundles of foliage that are so iconic in bonsai. As he drew front and side diagrams of them on the whiteboard, Peter pointed out that creating those perfect pads always begins with branch division, lots of division. But it’s not enough to just create division, it must be planned carefully. For instance, you have to bear in mind that all that division will add girth to the tree. Depending on where you begin the division, that girth will either be close in to the center of the tree where it looks good, or it will be far out at the ends of the branches, where it will only look good in the most extreme of compositions.

With that in mind, Peter turned to the least developed of his junipers and asked the audience to imagine where we would want the outer edge of the final canopy for that tree. He held his hands open around the tree to help us envisage where its perfect silhouette would be. With that goal established, he told us to imagine how much further in we would have to start dividing the tree’s branches to allow enough division and subdivision to create the dense pads achieved on a mature tree. He moved his hands in to where that would be, and many of that tree’s young branches were already bare beyond that point. Clearly, some of those branches were going to have to be sacrificed. Peter’s ultimate point: you might have to cut deeper into the tree to get the ramification to peak where you want it. Additionally, he added that you can’t work on one isolated area without regard for other areas, or else you’ll waste your time perfecting something that might end up getting sacrificed in service to the larger design.

Returning to the importance of working on healthy trees, Peter sidetracked to a discussion of spider mites and how to deal with them. Various types of oil are effective. “Year Round” and “Neem” are two popular examples. Peter recommends using only 60% of the listed dosage and avoiding using oils under direct sunlight. Douse the tree thoroughly, but then wash it off an hour later, again to avoid sun exposure. It will have done its job of suffocating the mites within that hour. Be sure to repeat the process a week later to catch new hatchlings. According to Peter’s experience, miticides (Floramite, Sultan, Hexagon) are less successful in the long run, the problem being that mites build up resistance to them over time. Peter also says that Malathion doesn’t work at all.

Our June presenter was Bill Castellon, a professional landscaper, aesthetic pruner, and shohin fanatic with extensive experience growing and pruning pines of all sizes and varieties. The topic of the evening was decandling black pines and Bill brought a vigorous young black pine for demonstration, which was raffled off at the end of the night.

Bill went straight to a discussion of decandling timing strategies and never gave the down-and-dirty on what decandling is and why it’s important. A quick explanation for those newer bonsai enthusiasts reading this: Decandling a pine means cutting the new growth shoots of a vigorous pine, referred to as its candles, so that when the needles developing inside of them open up later, they are noticeably shorter. It is done because simply cutting the needles after they are fully developed will result in unsightly brown tips on the needles. The proper timing of this procedure is a topic of much debate, with as many opinions as there are microclimates in the San Francisco Bay Area, but the one agreed-upon constant is that the later you make the cut, so long as you don’t wait too long and miss the developmental window, the shorter the needles you will get. Decandling is also done to encourage division, being the pine equivalent of tip-pinching on deciduous trees.

Like many of our other favorite presenters, Bill does not like to state absolutes like, “You must decandle in June.” Rather, he likes to set general guidelines and emphasizes that you must consider the individual tree and its specific environment. As an illustrative example, he points out that shohin artists in Japan wait until as late as July 15th to decandle, to get exceptionally small needles. They can do that there because their climate supports it, but here in the Bay Area, Bill suggests we don’t push our pine candling past July 4th at the absolute latest. If you decandle your pines too late, you’ll get malformed or otherwise unhealthy needles, or even an entirely failed growth tip that eventually withers and dies. When in doubt, or if you absolutely must go by a specific date, Bill says that June 15th is a safe time to decandle pines in our area.