NABF Newsletter #5

Feature #9

Satsuki Azaleas in the Northwest

By John Carleton, Jr.

Preface

The methods described in this article might be seen as iconoclastic. They are very different from previous teachings about satsuki in the United States. The goal of this teaching is to produce a beautiful bonsai which also happens to bloom. It is not the principle goal to produce a bonsai with flowers that has to be kept out of sight until the next year's flowering season.

As in the rest of bonsai, and in life itself, there is often more than one way to achieve a goal. The method I am advocating is the result of many years of careful study by sensei Tatemori Gondo, who has shared it with his students at El Dorado Bonsai School in Placerville, CA. I am pleased with the results I have had following these methods. Indeed, this method is the only one which both preserves beautiful branch taper and ramification necessary for good bonsai.

Nothing in this article is intended to suggest that other methods are "wrong" or that this method is the only "right" one. I remain interested in and willing to try methods used by all other successful growers of satsuki. I want to remain humble enough to learn from and incorporate their ideas into my own personal methods. Indeed, I have already begun adapting my own methods to suit the climate where I live, which is very different from both Japan and Placerville in central California.

A person cannot learn bonsai by reading an article any more than he/she could learn to play the violin by reading. This article can only deliver a brief summary of Gondo-san's teaching. The hours of hands-on classroom experience are essential to learning this method and are well worth the time and travel involved. I urge you to contact El Dorado Bonsai School at 530-295-0200 or edbonsai@onemain.com for class schedules and more information.

A Little History of Satsuki as Bonsai

The genus Rhododendron contains about 800+ species, by far the largest of the plant groups except for that of the orchids. New species are identified almost yearly as collectors search the mountains of southwestern China, Myanmar(AKA Burma) and Nepal. One of the most interesting of the many fascinating characteristics of this entire genus is its high probability for genetic "accidents" or "sports", which may partially explain the remarkably large number of species, color variations and flower and leaf sizes and shapes, and its promiscuous ability to produce fertile seed in hybrids.

Enter the Royal Horticulture Society, Kew Garden, London. Depending on whether the "lumpers" or the "splitters" are in ascendance this year, each "new" species is named and catalogued. Then periodically(oftener than once a century) the RHS decides to reclassify and rename some of the groups, genera, species, and sub-species with all their series, sub-series, etc.

Enter the hybridizers. Working with 800 species, the number of possible hybrids is "800 factorial" or the product of 800x799x798x797, etc., all the way down to x2. As you can imagine, this result is a very large number. Then if you start hybridizing the hybrids with each other, the resulting total seems to approach infinity. Naturally, the bonsai grower throws up his/her hands and goes off to trim trees or sharpen tools.

"Azalea" is a rather vague, generic term used in the Western World for a sub-set of species of Rhododendron characterized by having about the same number of stamens as they have flower petals. Nearly all of the plants we call "rhododendron" have two stamens for each flower petal. There are also some other less obvious characteristics: splitting of the leaf hairs, etc., which are not relevant to bonsai at all.

The Japanese are more precise in their descriptions of "azaleas". They use two names for these plants, not interchangeably at all. Those which bloom before starting their vegetative growth in spring are called tsutsuji. These are primarily used as landscape plants, often sheered to resemble large stones. Those which begin their vegetative growth before they bloom are called satsuki because of their later blooming period. ("Sa" is "five" in old Japanese; "Tsuki" is "moon" or "month".) Originally it meant the fifth month of the East Asian lunar calendar, New Year being celebrated during our February. Although Japan standardized to the Gregorian calendar in the late 19th Century, the term "satsuki" remains in use.

The mid-sixteenth century saw the beginning of the "Great Satsuki Vogue" in Japan and it continues right to this day. In 1661 the first book on "azaleas" appeared in Japan. Horticulturists already had a very good understanding of hybridization by the year 1700 and had produced and described over 160 named varieties. By 1999 there were about 1150 named varieties registered and still being propagated in Japan. Several more are no longer propagated in Japan, but continue to be grown in the USA and perhaps in other places.

Hybridizers outside Japan also produce excellent new varieties which are satsuki by the definition above, vegetative growth before flowering, but which neither have Japanese names nor registry, such as "Nuccio's Lucky Charm" and "May Showers".

Satsuki which have been developed and registered in Japan are usually given "poetic" names, not all of which can be understood or translated into meaningful English. "Kinsai", for example, means "Golden Award, Decoration or Medal" although the flower is bright red. "Aozora" is "Blue Sky" although the flower is purple and white. Kinsei" is "Golden Star", but the flowers are variegated white, pink and purple.

Most Japanese hybrids seem to derive from R. indicum, often sold in western countries as "macrantha" azaleas. These plants usually grow on rocky exposed ground in northern and central Japan, at higher elevations in places where there is not enough soil to support trees or other vegetation. They usually have narrow lanceolate leaves. This type of "azalea" is becoming fairly common in the Pacific Northwest and seems perfectly adapted to our temperate summers and mild winters.

In addition, R. tamurae, known in Japan as "maruba (round-leafed) satsuki", grows at low elevations in the southerly regions of Kyushu and islands stretching toward Taiwan.

These species rarely overlap one another, but they hybridize so easily that cultivators have little difficulty in producing an seemingly endless number of new leaf shapes, flower colors and color patterns, sizes and shapes.

Central and southwestern Japan have a hotter, more humid summer season than almost any of North America or Europe. Perhaps only the steamy Gulf Coast and Florida bear a close resemblance to the native climate of "maruba satsuki". I know that they are fairly scarce in the Pacific Northwest.

Flowers occur in all sizes from under 1.5" to more than 5" diameter. There are 22 different classifications of flowers by color patterns, shades and combinations in white, pink, red and purple color groups, and 16 flower forms to choose from.

But enough of taxonomy! This article is about bonsai!

Satsuki: General Care & Feeding

1. Soil

2. Watering:
When? How much?

3. Fertilizing

4. Pruning, Wiring, and Bending Branches:
When? Brittleness: How to force budding on leggy branches?

5. Repotting:
Time of year? How often?

6. Flowering and Trimming:
When?
Special techniques before flowering
Special techniques after flowering

7. Summer, Autumn and Winter Care

8. Suggested Further Reading

Soil:
Kanuma or not kanuma, that is the question. There are many grades of kanuma around: some sifted and some not, some very coarse(over 1/4" diameter) and some graded medium and/or small. Straight small kanuma does not allow for adequate aeration of the roots. A mixture of mostly medium with a little small is better than all coarse, which is only useful as a drainage layer at the very bottom of the pot. Be sure to sift out all the dust before using kanuma as a potting medium. Beware when shopping. Remember that you generally get what you are willing to pay for. Something that seems too cheap probably is just that, too cheap to be of much use.

Remember too, azaleas have been growing all over the northern hemisphere for millions of years without the benefits of kanuma. Any soil mix which provides good drainage with moderate moisture retention, basic nutrients and moderate acidity will support these trees extremely well. In rainy climates peat is the one soil amendment most likely to spell trouble. Once it gets wet, it stays wet almost forever, but once it is dry it is nearly impossible to dampen without drowning the bonsai's roots. Over-wet soil leads to root rot, root rot leads to a dead tree.

The best basic guideline is, if the tree is growing in kanuma, repot it into kanuma. If it is growing in some other bonsai mix, repot it into that type of mix. Any soil mix will work as long as all the fines are sifted out, the pH is below ~6.7, and there is quick drainage and good aeration with moderate moisture retention.

Top-dressing must be applied to kanuma or it will wash away during watering. Chicken grit, turkey grit or small crushed lava rock all work well. Chopped green moss may also be used.

Watering:
This is definitely the most critical part of care for all bonsai, but it is especially important with satsuki. Water with dissolved salts (pH greater than 7.0) causes trouble. Over-watering kills many more bonsai than not watering enough, and the soil mix is very critical to success or failure. A slight drying between waterings is beneficial. The best test of the proper time to water is to wait until the soil surface feels slightly dry. Then poke a finger about 1/2" into the soil. If it feels only slightly damp, it is time to water thoroughly and watch to make sure the water drains freely through the pot. Drench the foliage at the same time, except when flower buds are opening. Wet blossoms are subject to brown blight fungal disease. Remove spent blossoms immediately, and in severe cases of blight, remove all the remaining blossoms and buds and treat the tree with a fungicide.

Fertilizing:
There seems to be a lot of unnecessary controversy in the bonsai world about whether to use "organic" or "chemical" nutrients for bonsai. Plants are "autotropic", which means they synthesize their own food in the chlorophyll in their leaves, needles, trunks and branches in the presence of light. Our job as bonsai growers is to provide the nutrients to make healthy growth possible. Chemical fertilizers are available to the plant as soon as they are dissolved in water, but it is easy to apply them in a too-strong a concentration. Weak solutions, less than 1/2 the manufacturer's recommended dilution, are a good counter to this problem. Organic fertilizers must decay into their basic chemical elements and molecules before the roots can absorb them. Since that decaying process is rather slow and complex, use of organics will be less likely to harm to the bonsai with a chemical overdose. However, insects, rodents and pets often make the use of these fertilizers impractical. Chemical fertilizers may be diluted to safe levels and administered whenever the bonsai is watered. Fertilizers in a water solution are applied to already damp soil, and those in dry, pellet form are added to dry soils before watering. Apply fertilizer in liquid form once or twice in the early spring before transplanting time.

Whenever a tree is going to bloom this season, do not fertilize it after the first week of March. When it is has bloomed for ten days, remove all spent blossoms, the rest of the flower buds and the seed pods. At that time fertilize lightly in early summer. Applications of a 0-10-10 fertilizer in late August are helpful while the tree is forming next year's flower buds. Bonsai become somnolent when temperatures reach 90F, so applications of fertilizer are useless until cooler weather returns.

Pruning:
Whenever pruning is done on any smooth-bark tree, make clean cuts with a grafting knife or sharp chisel to promote healing and seal all cuts 1/8" or larger with a good putty-type sealer.

Trimming, wiring and bending branches should be done in sequence, one right after the other in early spring. If the satsuki has small, very narrow leaves, this can be started before the 1st of March. Trees with slightly broader, somewhat larger leaves should wait until mid-March. The more round-leaf varieties(called maruben) can be done toward the end of March. Any trees in the "Osakazuki" family should not be done until after the 1st of April. This last group does not respond well to heavy pruning and is generally be treated with "kid gloves": light pruning and trimming, later in-the- year repotting, and more protection from extremes of cold, heat, drying winds and hot sunlight.

Pruning back of heavy branches must be done in stages. The first year, in early-to-mid fall, cut back to several short green secondaries on the branch. Always seal cuts with a putty-type cut paste. The next year cut the branch shorter, leaving only one green shoot intact. In the spring of the third year, cut the branch back to a short stub and seal it well. In the spring of the fourth year the stub can be cut off flush with the trunk and the wound sealed again. Even then it may take several years for the scar to heal.

Because satsuki have very tightly bundled vascular systems, never try to remove two branches on the same vertical water line at the same time, i.e. branches directly above and below one another on the trunk. It could cause the death of that entire side of the tree's roots and branches. A "Go slow!" approach will yield the desired result by allowing the tree to re-route its watering and feeding lines.

"Back budding" on leggy branches is easy to achieve. Right after early spring fertilization, cut the branch back to a pair of strong shoots and then expose the tree to some warm sunlight. The satsuki will take over from there and in about five weeks many new green buds will appear. Keep the ones in all the good places and rub off the rest. The most pleasing arrangement is achieved by having the first secondary out from the trunk go toward the back of the tree rather than up or toward the front.

Wiring and Bending Branches:
Because of their thin, easily scarred bark, only aluminum wire is safe to use on satsuki. Applications of heavy wire can lead to scarring and wire cuts. Special care is required. All "azaleas" have brittle branches when they have been recently watered. To overcome this hazard, bring the tree into a cold, dry area for about two or three days before wiring and bending any branches. Also note that branches will bend more easily without breaking if they are given a slight twist along the axis at the same time as the bend is applied. Before applying wire, decide which way the branch will need to rotate and apply the wire so that it will tighten slightly as the twist and bend are positioned(see Figure #1).

The time for wiring and bending is early spring, just before repotting. To achieve a pleasing, natural effect, branch movement is usually slightly upward as separates from the trunk, then smoothly horizontal or downward as desired. Branch tips should always be wired to the very tip so that even on a cascading trunk or a drop branch the tip buds can be turned slightly upward.

A branch may be moved to a new position by several small adjustments over the course of several weeks or months with much less chance of breakage. It is also possible to use guy-wiring to lower larger branches or move them from side to side. This can be done by inserting a guy of thin copper wire through a loop of a wire already spiraled along the length of the branch. This will distribute the load along the branch safely without scarring(see Figure #2).

Repotting:
If the tree is young and still in development it will benefit from repotting every other year. Older trees, after several years in a pot, may be repotted less frequently, about every third year. Stop watering for about two or three days before repotting. Except for a very light application of steamed bone meal to stimulate root development, all fertilization should be withheld for four weeks after repotting.

The tree is ready for transplanting as soon as its spring growth cycle starts and the wiring and bending are done. Begin by preparing the new pot, placing screen over the drain holes and affixing tie-in wires(see Figure #3). Mica pots are ideal for satsuki training because of their insulating properties, ease of adding holes for tying-in, availability, and economy.

View from bottom of pot

Remove the tree from its old pot and loosen the old soil from around the outer edges and bottom of the roots until you have a left a pad 2 - 3" thick(larger tree = thicker pad of roots) in a flat pancake shape about 2" smaller in diameter than the new pot. Using a sharp shears, trim the edges and bottom of the root pad so that all torn and damaged stragglers are removed(see Fig 4).

Place new soil in the pot, firmly seat the tree in its new position in the pot. Begin to tie it in loosely by drawing one wire over and twisting it to the next tie-in around the pot until you reach the first wire again. Now, cut a shorter piece of "bridge" wire and twist it around the first wire. At this time fill the pot with soil and firm it slightly. Plant the tree deeply enough to cover up the nebari(the crown of spreading roots at the base of the trunk). Then hold the trunk firmly in place as you proceed to the next steps. Pull the bridge wire back to meet the last, unsecured tie-in wire. Twist these pieces together to take up slack, stop twisting and pull outward to take up the rest of the slack. Then twist them together again to hold the tree firmly in place(see Figs 5A, 5B).

Top-dress the soil if necessary and water the tree in thoroughly until the water runs clear as it drains. Tying the tree securely into the pot and top dressing the soil will keep it stable and allow the very fragile new roots to begin growing without being broken or torn. After repotting protect the tree from winds and strong sunlight for three to four weeks. Mist the foliage daily or oftener, but allow the soil to become almost dry before watering again moderately. Overly wet soil inhibits new roots from forming. Protect the soil from freezing temperatures and move the tree gradually into more sunlight when new green buds and shoots appear in three to four weeks.

N.B.: Every year in which a satsuki has been repotted, when the flower buds show color, remove all of them. This stimulates the next phase of foliar growth to guarantee a strong recovery from the repotting.

Blooming:
Attend to the tree's watering carefully during the blooming cycle. When the flower buds show color and when flowers are open, discontinue overhead watering and water the soil surface only. Additional water will be needed during the growth and opening of flower buds.

In years when a satsuki has not been repotted it may be allowed to bloom. As the flower buds begin to show color remove about half of them, keeping the correct balance to be true to the varietal name. For example, "Kaho" should bloom predominantly white with a scattering of pink, purple and variegated blossoms. If other colors besides white begin dominate a branch, those buds must be removed to prevent a complete takeover. Also, remove those flowers which open too far in advance of the "show date" so that the maximum number open all at once. After the tree has flowers open for 7 to 10 days, remove all the flowers, remaining buds and nascent seed pods. Fertilize lightly, and wait for the new shoots to begin growing.

After flower trimming:
Satsuki usually produce five new shoots at the base point where each flower bud has been removed. Usually only two of them are retained. If a branch needs additional length for the bonsai design, keep the longest and strongest plus one other. But if the branch is already long enough, remove the strongest shoots or trim them back to one pair of leaves each soon after their appearance. At the perimeter of each branch keep shoots which are either horizontal or which grow slightly upward. Those which grow strongly downward can almost never be wired to produce a "natural" part of a design, so trim them off. Behind the outer perimeter of branches keep a few of the shoots which grow upward also to develop branches and secondaries which have more depth and texture than flat fans.

Continuing Care:
Through summer and autumn satsuki require protection from hot afternoon sunlight and drying winds. Shade cloth may be required. It is also a good plan to use fence boards to shade pots from strong sun. Ceramic pots do not provide as much protection from heat as mica pots. Many professional growers in Japan transfer trees into ceramic pots before show time and then back into mica ones for the balance of the year.

Many satsuki are quite hardy and will withstand frost easily. The hardiest varieties have smallest, narrowest leaves. The wider, longer and rounder leaf types will need the special protection of a roof overhang, cold frame or an unheated greenhouse. Mulching around pots is beneficial as long as it does not become water-logged or inhibit drainage. Trees from the Osakazuki family must be carefully protected from freezing at all times.

Further Reading:

Galle, Fred C., AZALEAS, Timber Press, Inc., 1999, ISBN 0-88192-091-6
Kennedy, Alexander, FLORAL TREASURES OF JAPAN: the Satsuki Azaleas,
Splatt Press/Stone Lantern Publishing Co., 1997, ISBN 0-95251-45-2-4

2003 John Carleton, Jr.
all rights reserved.