Don, I found a more detailed pst in response to a similar post last summer, hope it helps. John
Larry, you really need to pluck in the summer and the fall: Here is my epistle for the ABS/BCI Black Pine workshop I am doing in Denver next week:
Black Pine Bud, Nee dle and Growth Management
John Kirby; ABS/BCI, 21-24 June, 2012; Denver, Colorado
Why do we remove spring candles from Japanese Black (and Red) Pines?
Spring candles are the strong early growth seen in Pines following their winter dormancy. On rapidly growing trees, these candles can shoot to 18-24” in a single sustained growth spurt, resulting in new wood and needles of 6” or greater length. Why does this happen? Like most trees, in contrast to “shrubs”, JBP are apically dominant and strive to grow both up and out. This results in a tree with a strong and wide canopy, with little internal growth on mature trees. Why is there little growth internally and lower on the tree, except at the end of branches? Two prime reasons, the first is that the strong canopy shades the internal portions of the tree and the lack of sunlight results in the loss of internal foliage and the lack of new bud development. Second, the hormones (auxins) produced by the apical buds (the strongest growing buds) inhibit the growth and development of lateral and secondary buds, thus latent or dormant buds, are not likely to develop spontaneously while the apical buds are active. Unlike the mountain pines, Ponderosa, Japanese White Pine, Limber Pine, etc., the Japanese Black Pine has a very aggressive pattern of growth, this is most likely a result of its living in more moderate climates than the mountain pines. The Japanese Red Pine, also a pine from more mountainous regions has an intermediate growth pattern but is highly amenable to bud management techniques. All of these pines require full sun for optimal growth and some level of winter protection.
So why do we remove spring candles from JBP (and JRP)? We remove candles to do four main things
1. To stimulate back budding and the activation of dormant “adventitious” buds on the woody branches of trees. This is done to shorten branches and make trees more compact and to stimulate and aid in developing branch taper and movement.
2. To regulate the structure and pattern of growth of branches. When you remove the apical bud (aka spring candles), the resulting new candles, known as summer candles, have a shorter barren “neck”, that is the barren, budless, space between subsequent years or cycles of growth is shortened. This results in shorter internodes. As the latent or adventitious buds are found at the base of the candle, shortening the internodes can result in a denser and more highly refined branch structure.
3. To reduce the length of needles on the tree. JBP can have needles that are very long (6” or greater) , on a very, very large tree the long needles may be useable, however on smaller trees the needles are always out of proportion and when cut have a brown tip. Prior to Mr. Suzuki’s (Daiju-en, Nagoya, Japan) development of the summer decandling protocol, needle length in JBP was controlled by restricting water and fertilization and by allowing the tree to be very highly root bound. This process was extremely stressful and often lethal to the trees. It is now possible to easily maintain shohin JBP bonsai with needles less than 1” in length, or larger trees with needles 2-3” long as needed. In fact, it is possible to get JBP needles too short for big trees, therefore, timing and consistency are very important.
4. To facilitate the development of uniform strength, needle length and density from the apex to the bottom branches of the tree. Without using the decandling technique this is almost impossible to do on JBP
So how do we decandle Japanese Black Pines? What are the preparatory steps to the process?
First of all, to prepare JBP for decandling they must be strong, have healthy root systems and be free of obvious disease. Like all bonsai, JBP need to be planted in a rapidly draining yet moisture retentive soil mixture that has good oxygenation. I personally use an akadama, hyuga or kiriyu and volcanic (scoria) blend that has added charcoal and no organic component for all trees that are in bonsai pots. Other mixes work just fine if they have the key attributes of rapidly draining, moisture retentive and well oxygenated. Next, JBP need to be well fertilized and watered. I fertilize with both organic and defined chemical fertilizer (osmocote) beginning just as the trees are waking up and continue fertilizing until the day that the trees are decandled. JBP also like to be well watered, the old school approach of withholding water is dangerous to the health of your tree. You need to balance watering with growth and health, however if JBP are in a good soil mix they are difficult to over water, particularly when growing. When the spring candles are removed, we remove the fertilizer and then replace it 4-8 weeks later depending on climate. I also do preventative systemic insecticide (like an imidacloprid granule) and fungicide (a rotation) treatment.
So the take away from this is that we are working to have a young and vigorously growing root system coupled with young and reliably growing foliage all attached to aged appearing nebari, trunk and main branch system.
One additional step that you can take is to pinch the overly long spring candles in preparation for summer decandling. The timing of this can vary, typically we pinch overly long candles in late April or May, your timing can vary depending on your climate, how you winter your trees, etc. By pinching candles I mean if you have candles that bolt to 4-6” or greater, a good way to balance growth is to break the candle with your fingers. This should be done above the lowest needles that are starting to form, leaving the needles will allow the candle to continue to grow and inhibit the development of summer buds until the timing for decandling is right. If you have candles get away from you, get very long and then have the needles emerge before you can pinch there is a second strategy. For those candles, after the needles have emerged pull all of the needles except for a dozen or so pairs at the very tip, that will keep the candle alive until the correct time for decandling, yet limit the energy it is capturing and help to balance growth. These pinched candles will be treated the same as the others when decandling occurs.
So when do we decandle Japanese Black Pines?
Well, that depends on where you live and how big your trees are. If you have a range of sizes, from shohin to very large (3+ feet tall) ogata-bonsai, your decandling timing will extend over a period of several 2-4 weeks. In northern US and high altitude locations, we typically start decandling in early June and finish up by mid to late June. When I lived in Arkansas, I would start in mid to late June and finish in mid-July. What determines when you need to decandle? The critical factor to consider is when will growth stop in the fall, when will the needles be hardened off by the transition to fall. Why? You want your needles to be hardened off and fully ready for winter, you also want to have a reliable period of known growth so that the needles will grow a predictable amount before they stop and harden off. This means, the later in the fall that trees can reliably grow to, the later in the summer the trees can be decandled. Make sense? So, when we decandle we start with our largest trees (and cork bark (nishiki) pines as well), transition to our medium sized trees a week or so later and then our small (kifu) and finally shohin trees. For some this may seem counterintuitive, however, let me say it again- we start with out largest trees and proceed to our smallest trees. The last trees done should be the shohin/mame trees.
So how do we decandle Japanese Black Pines ? (and Japanese Red Pines)
There are a number of techniques that can be used, including dividing a tree into strong, medium and weak zones and removing candles by zone on a 10-14 day interval, so you would start by removing the weak buds first, followed by those of medium strength about 10 days later and finally the strongest candles 10-14 days after the medium. The trees needles are then balances with fall removal of old needles and typically a spring reduction in new needles as needed. Variations of this theme are common and have been used for a number of decades. Remember we start with the weaker buds because we assume that it will take them longer to develop to a common stage of development than those from the stronger areas.
The approach we are going to use here is different. It is an approach used by many today because it allows you to do all of your work on a given tree in a single sitting. What we will do is to remove all of the candles in one day. Please note, very weak or internal buds will not be touched- they will be left for next year. How do we do this? We start at the top of the tree and work down. We are trying to balance energy and to stage the timing of summer candle growth. Back to the top of the tree, using sharp scissors start cutting candles, please ensure that you cut the candle square to the end of the branch. -The strongest candles are cur so as to be left with the longest “stub”, that is moving up the candle from last years needles, there is a bare neck with no needles. This tissue is producing some of the auxins that the apical buds use to slow down development of the adventitous and lateral buds. By leaving a ¼” to ½” long stub we allow the tissue to continue to produce auxin and slow down the lateral buds at that point, but not produce so much auxin that he impacts more distant buds. This stub will dry our over the next two-three weeks and then new buds will activate and develop. As you move to the medium strength candles, you will leave a shorter stub, about 1/8-14” in length and finally on the weaker, smaller, buds we essentially leave 1/16-1/8” of tissue. Again, leave the weakest and internal buds alone if needed.
After all of the buds have been removed, we move back to the top of the tree. Using straight tweezers, we begin to remove needles. How many needles that you leave will vary on climate, tree, and goals for the tree. When you are first starting to do this, I am asking that you leave 6-8 pairs of needles at the top and on the strongest points, 9-10 pairs of needles in the middle strength areas of the tree and 11-12 pairs of needles on the lower part of the tree. When you pull the needles, grasp both needles and the sheath with your tweezers and pull them in the direction that the needles are growing. This will result in a clean branch end. Unlike Ponderosa or Japanese white Pines, it is not recommended to cut the needles off of JBP.
When you are done, it is best to sit back and look to see that the tree looks balanced from side to side and that the tree will tend to have more needles on the bottom branches than at the top. You should expect to see new buds emerging in 10-14 days or so, on strong trees you should see a number of buds emerging at each point where a candle was cut, and some may also appear on interior branches.
What is the next step? Fall work.
After the summer candles have grown, you will notice that they will be more compact and the stem (neck) will be shorter. You may also have numerous candles at each point where a spring candle was removed. In fall work, the first step will be to reduce the number of candles at each branch end to two. It is best to remove all candles that grow down (off the bottom of the branch) or straight up, if possible. Essentially, you are developing a fork at each branch end, in addition to the up and down buds, it is best if you can two buds that are fairly equal in strength. Hint- leave smaller candles towards the top of the tree and larger candles towards the bottom of the tree.
After the summer candle numbers have been reduced, it is time to remove all of the old needles. Using the straight tweezers, pull all of the old needles (those that you left on the tree when you cut the spring candles), again grasping both needles and the sheath, pulling them the direction that they grow. You may also chose to remove new needles from the strongest candles, not as many as in the summer , but reducing their number to limit spring candle growth to a more consistent level. Continue to feed the tree until it becomes dormant, then complete your fall work by cleaning the fertilizer, weeds, moss and trash from the soil surface and replace it with a clean covering of new soil.
Trees that will be shown in the Winter (December-March) should have their old needles and extra candles left on the tree until after the show to improve foliage density. Fall work is then done after the tree has been shown.
Decandling is a stressful procedure for pines. The stress is counteracted by the prolonged period of fertilization, watering and good sunlight. It can take a few years for your tree to stabilize and have uniform growth. Three to five years should get you a good deal of stability, this will however be affected by wiring, repotting, major restyling events. If you ever have a year where the tree doesn’t grow normally in the spring, poor or no candle growth, leave it alone. Remove old needles in the fall after candles grow and harden off, or if you get no candle growth, leave it completely alone and check to ensure it is draining well, etc.
Finally, styling Japanese Black Pines (and Red Pines) can be done most easily in the dormant period (December to March) or immediately after decandling, as long as care is taken to not damage the remaining needles. Strong trees can be wired in the late summer and fall, however the utmost in care must be taken to prevent needle damage.
I have not invented or discovered any of the techniques described herein. I have benefitted greatly by studying with Boon and learning and implementing these techniques over the past 8 years. There are numerous publications, online blogs and study groups, that have covered this topic as well. I annually review Boon’s DVD on Decandling Japanese Black Pines (www.bonsaiboon.com
) to refresh my perspective as I begin to do summer work.
Good luck and good plucking!