Cambial activity shuts down first at the top of the tree, then in the trunk, and lastly in the roots. Therefore a tree may well have an active root system well after visible growth or leaf drop has occurred. Also, the upper roots of trees in the ground are the first ones active in the springtime.

Makes you think, doesn’t it? Another complicating piece of the puzzle is that the top of the tree is much more cold hardy than the root zone. The tags we see on nursery containers that read ‘Hardy to_’ assume you will plant it in the ground, where tree roots are designed to be. Those cold ratings are for the top only; roots are more tender. Quite a cautionary tale for those growing bonsai. Roots are calibrated to be in the ground, not in a pot.

There are a couple of important lessons here. While light frosts in the fall will ease a tree into dormancy, unseasonably deep cold in the fall may kill the tree because the roots are still active. Spring is the usual time to be careful of hard frosts, but fall must be watched too. Furthermore, if we live in a mostly mild climate with infrequent arctic blasts we should be aware that bonsai may never go fully dormant, retaining active roots throughout winter.

Healthy roots of most hardy trees and shrubs are fine with light frosts in the upper to mid 20′s (F), which helps to ease them into winter dormancy, but lower than that they need better protection such as placement on the ground or in an unheated room, greenhouse, or coldframe.

Those bonsai spending their winter holidays out on the benches may need a careful weather watcher (that would be you!)

(Reference: Tree Maintenance, P.P. Pirone, 1988)

'yaaaaaaAAAA!' ---The sound of a pleased wisteria owner

Wisteria bonsai fail to bloom for several primary reasons. The first is that people tend to repot them too frequently. Keeping the wisteria a bit root bound is important—in fact, you should not repot your wisteria more often than once every five years or so.

That’s the first thing. The second is that wisteria need a lake the size of China to be happy. Give your tree a lot of water by immersion of the lower part of the pot in water during summer. DO NOT leave them soaking year round. Without resting the pot in a basin of water the tree won’t flower much the next year. Oddly, the roots don’t rot. (In Japan they have watering drones called apprentices, who can water in their sleep if necessary. If you don’t own a drone, and don’t wish to water 28 times a day yourself, it is perhaps best to use the immerse technique for the summer growing season.)

These first two practices must be combined: If you don’t repot frequently, the soil will get compacted (which we want for good flowering) but that compaction will make it very difficult to water sufficiently from the top when the tree needs a lot of water, in the summer. Hence the pan underneath.

The third thing to promote consistent blooming is to be careful when and how much you’re fertilizing. It is best to fertilize strongly AFTER FLOWERING (April/May) until about July, and then slack off. That way your flower buds will set for next year, and you will restrain foliage growth over the summer.

Lastly, the wisteria will usually produce some tendril growth, which if encouraged will shift the plant into a vegetative growth habit and reduce flowering. Nip these tendrils back to prevent too much growth.

Keep the darn things in the sun. Put up big fans to keep the clouds away. And then watch them bloom.

Maybe I should have titled this one ‘Preventing the Umbrella Rack!’ —but that would have been only slightly better than last week’s overly ambiguous title.

The quintessential connoisseur...a kind of art snob that you'd probably hesitate to invite to dinner, but who tends to be insightful.

For bonsai, this discovery or insight would be an over-looked plant for bonsai. I think relatively unknown plants sit at the periphery of the mainstream species until proven. Tradition is a wary animal. It wants it’s own proofs, like the essential repeatable experiments of science. For bonsai, those proofs would be:

- non-flashy aesthetic

- easily cultivated in a pot

- responsive to technique

- long-lived

- at least one season where it shines, even if during the others it looks horrible

- and a lot of people (connoisseurs) agreeing on those points (this is a tradition after all, not a one-man show)

Let’s take the example of Chojubai quince, from last week’s post. In the third paragraph of that post there was a historical note indicating how it’s popularity grew over some decades. I think that the great popularity that this plant now enjoys in Japan is two-fold: One, it meets all the criteria above. Second, it mirrors a rare aesthetic really only represented by one other plant: Ume, Japanese flowering apricot. Both are plants of unique contrasts, having roughened, craggy bark and trunk, yet producing the most delicate, simple flowers at a time of year when all else looks dead: Winter. Connoisseurship—the recognition of rare qualities—in Chojubai has prompted its rise to ‘appreciated plant’ status. All bow…

Well, I have my own reasons for being in love with Chojubai, and grow it avidly. But I suggest taking a good look at something you like—an under-appreciated plant, perhaps a native—and really push its possibilities. Take it to absurdity. And then see if you can convince your bonsai friends of its validity as a front-ranker!

If you become a connoisseur of something, it changes everything. It changes how the plant looks, because now you’re really attending to it, focusing attention and technique on it. And, just maybe, you might even change our communal perception of beauty.

A well-known root-over-rock Japanese flowering quince 'Chojubai'. 45 cm high

Fairly typical of the multiple-trunk old Chojubai now seen in Japan. 33 cm high

Chaenomeles japonica ‘Chojubai’ is a cultivar of the comparatively coarse Japanese flowering quince. Few plants for bonsai can match its contrasting qualities: Idiosyncratic, craggy branching and twigging, with rough older bark, adorned almost contradictorily with glowing ruby flowers. They flower mostly when out of leaf, in winter, so they lend a feeling of glowing life to the bonsai yard when all else is dull. The details are small, with glossy leaves about 1/2″ long and flowers under 1″ wide. There are several flower variations including white and red, although almost all Chojubai used for bonsai are red-flowered because that variety has the finest twigging.

Medium-sized ('chuhin') Chojubai. Fine old tree. 29 cm high

Quirky medium-sized raised-root Chojubai. 30 cm

The history of this tree in Japan is interesting… At first, Chojubai appeared commonly as a small accent plant in the Kokufu show forty years ago, as an unramified twig or two. Only rarely was it seen as a primary tree in the medium size category, and never in the large size. It was a second tier tree. Then something shifted. Around 1990 we began to see large size Chojubai in the Japanese shows. These were trees about 1-1.5 feet tall and twice as wide, multiple-trunked and highly ramified. Occasionally single-trunked trees, which are rare, were seen. In Kokufu book 80, about six years ago, two Chojubai won Kokufu prizes. Two years later in book 82 another won. Chojubai had come of age.

Most Chojubai are enjoyed out of leaf, although the small glossy leaves are perfectly in scale. As Chojubai often flowers nearly year-round there is nothing stopping you from putting them on the display tables any day of the year. 30 cm

You might wonder why I put this in...Well, it is a Chojubai accent plant in the Kokufu show 40 years ago. Interesting, isn't it, how tastes and techniques have changed? These days, this tree would be unlikely to even get accepted into a local Western show.

The vast majority of Chojubai grown for bonsai are the red-flowered variety; all the other photos in this gallery are of red-flowered trees. This is a white-flowered tree and it won a Kokufu prize. Very hard to ramify the white ones. 33 cm

Chojubai’s ease of ramification is enhanced with training, creating dense forms of intense complexity. Most unique to the Chojubai is the natural eccentricity and unexpected angles and directions in the branching, which are usually encouraged as they represent the special flavor of this variety. If this were a plant trained by music, that music would be jazz.

A red-flowered Kokufu prize winner. Very old. This is a good example of the extremes in technique used to create a very crystalized form. Impressive, and yet in some ways perhaps not showing the best of what Chojubai offers. Hmm, I wonder how long I will be in purgatory for that comment... 35 cm

One of the rarer single-trunked Chojubai. Another Kokufu prize winner. If you have a single-trunked tree, be very sure to cut all suckers that come from the root base. Beautiful old tree! The warty bark is evident only with great age. 38 cm

If you have a Chojubai, you’re lucky. Keep it moist. Plant in deeper containers to hold more water. If you have a young plant, put it in a big training pot with large size soil mix for a few years, so you have some energy to manipulate. Keep in the sun. Use a pesticide when shoots are elongating to control aphids. Wire main branches and shoots from the base for multiple trunks, and cut and grow following that. This is not so much to create branch taper, as there will be little of that, but for the short, zigzagging and erratic branching that is only created by many years of scissor work. Leave one to three internodes only. Always immediately remove shoots that come from the base that you are not intending to use as trunks—they will weaken the older areas. There’s more to it, but that will get you started.

Lovely loosely styled multiple-trunk Chojubai. Many years of careful scissor pruning created this natural form. 40 cm

Chojubai just beginning to grow in April at Shinji Suzuki's nursery.

Another Chojubai at Suzuki's a month later, in May, just before trimming the extensions.

Chojubai at my place in mid-December, showing tiny flower buds. Any strong tree, with timely trimming, will produce this many buds. It has already had a few flowers open, which are about 1" across, and will continue blooming for 3-4 months until late March when the leaves start coming out. After that the blooming is more sporadic.

After all those words and photos, there’s no hiding that I’m totally besotted with Chojubai. Ah well. Another personal secret offered to the globe. But I have a wondering curiosity if these images stirred—if any photograph CAN stir—the endearments that Chojubai have raised in myself and others lucky enough to have seen them in person. I imagine many of you have never seen Chojubai before. What do you think? Something you’d like to see more of?

Many of you may remember this Foemina juniper from old photos of California bonsai shows, or even last year’s Bonsai Statements magazine. It has a thirty-year history as a bonsai, created in California by the eminent Shig Miya from an air layer. Mr. Miya grafted the only branch at the top of the tree.

Deciding on this aesthetic shift for Mr. Miya’s tree was derived from a simple conversation about its possibilities with my client, who had purchased the tree several years ago. We were both eager to try a new form. My client is very interested in preserving old bonsai created in the States, but he also likes adding new twists to old things. I think bonsai develop an indefinable flavor when they’ve been worked on by multiple artists.

I am not a proponent of keeping bonsai as they are, indefinitely, in perpetuity, as a form or creative idea that was locked into place by the first artist. Bonsai are BONSAI precisely because many people, hopefully, lend their artistic stamp to it, and the bonsai change and morph over the decades. This is what makes a bonsai different from a novel or a painting. I know this is an issue of some contention particularly in public bonsai collections, where, understandably, there is an effort to retain bonsai looking like they did when donated. This presents great difficulties, however. It seems to me that if a bonsai were, to use an extreme example, to lose an important branch, then to have it remain locked in its old form even though visual balance has been lost would be to allow it to devolve into bad bonsai. And bonsai change without asking for our approval, too.

I think the only rule is to be continually seeking to find balance within the tree, within the design. And everyone’s sense of balance will be, naturally, a bit different.

The Foemina juniper on the Sept/Oct 2010 cover of Bonsai Statements.

Photo of the Foemina juniper from a show a few years ago, in the original design.

Current design, fall 2011. The lower right jin may be shortened in the future. My feeling was the apex should be lower than the top of the trunk, and that the cascading branch was too long. I hoped these changes would highlight the massive, straight trunk. And I wanted to see more integration of foliage and trunk, so that it appeared more as one unit. It needs perhaps a bit more growth to complete that last goal. Please comment freely and honestly!

One of it’s few defects is a strong root on the right. I’ll have to discuss this with my client, but I may split it and lower it, at the same time raising the entire tree by half an inch next time it’s repotted. That way I hope to expose some of the other nebari roots and make them all at about the same level. Did that make any sense? Splitting the root will make two roots…and easier to lower.

Anyhow, here’s the tree as it looks this fall:

Seedling Japanese white pine, shikoku variety, before rewiring in fall 2011.

After wiring. The shoots still show quite a bit of strength so it will not be repotted for another year.

Control is three-fold. The first is keeping your Japanese maples strong, healthy, and damage-free. The second and third are related: If you can keep your tree dry during wet and cold periods, that is half the battle. The other is chemical control, which is by copper sulfate or similar bactericide. ZeroTol (an oxygenator, essentially a very strong form of hydrogen peroxide) is excellent. Top spray and bottom drench is recommended.

If you have problems with this disease, try a chemical drench after repotting or after heavy root work. And if you live in an area with wet, cool weather in the fall through spring, seasonal prophylactic spraying is a sharp idea.

Clearing away leaves and especially seeds of maples—like bigleaf or vine maple—is essential after leaf fall as these commonly planted landscape trees are frequent carriers of the disease. Keep leaves and moss away from trunk bases, too.

The purply-black tissue damage of the Pseudomonas bacteria shown on this branch is typical of the disease.

Discolored stem damage above and below a pruning cut (seen as a white stub) where the bacteria likely entered the Japanese maple.

I’ve been surprised how well Ponderosa develops here in the Northwest. When I first moved here in 2006 I assumed there would not be enough sun to really get the budding and shorter needle growth on these pines, but having worked on a few now over a few years I have another opinion. This one will need only another three years or so of growth before it feels settled into this new styling.

Ponderosa pine before wiring

And after styling. Tree is tilted to the left to prevent vertical/horizontal sections of the trunk, and to create better drama in the flow to the right. Apex needs several years of growth to fill in.