FOREWARD: The first part of this article is about the maintenance of the Japanese Black Pine, and the techniques I describe here can, with some small adjustments, also be used for Pinus sylvestris, Pinus mugo, Pinus nigra, Pinus uncinata, and Pinus ponderosa. The second part of the article is focused on the Japanese White Pine, Pinus parvifolia.

First, before I start: I know that what I write works because it is what I do successfully with my own pines. But, I know that not everybody lives where I live, and that climate and seasons differ greatly around the world. However, I do believe that the techniques remain more or less the same, so you only have to adjust the techniques to your own local situation! Here is where I ask for the help of some knowledgeable colleagues in other zones of the world: I would greatly appreciate if they could answer the specific questions about those things like local growing or weather circumstances when they are asked? I kept it all as basic as possible, and straightforward so that everybody will be able to understand it easily, and they will have no problem applying the techniques I describe on their own trees! All the techniques I describe must be done every year (except on a young tree that needs to grow), There are many different ways to balance your pine and for needle reduction, etc. I think that the ones I describe here are a good place to start for any novice.

Before I go in to the energy balancing techniques, I must explain the different energy zones of the pine tree.

Pines generally grow irregularly upwards in search of the sunlight and when they mature they will grow more horizontally. If we look at the pine tree as a whole, we can tell that there is a significant difference in growing strength between the outer tips of the branches/tree and the inner part of the branches/tree. This difference is a result of the outer parts receiving more light and air than the inner parts, which have to live in the shade of the other branches that block out most of the light. Another factor is the pine’s natural growth pattern: favoring the branch tips and apex of the tree.

As with all living things in nature, only the strong will survive! Those strong zones play a much bigger part in the photosynthetic energy process than the weaker zones; therefore, they are more important for the survival of the tree, so the tree needs those parts to flourish and will send more energy to those important zones. The weaker zones as a result will get weaker and weaker and eventually die back. This is a natural process, but don’t worry: with the techniques I will explain, we are going to balance every part of the pine, so that ideally every part of the tree becomes equal in strength!

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Care and Maintenance

Pine maintenance is all about mastering the techniques for balancing growth energy within the tree. As with all pine bonsai, candle pinching, candle removing, needle plucking and pruning are very important to keep the tree healthy and well balanced.

So let's pretend we are starting on a more or less virgin specimen or neglected tree. First, you must look closely at your tree and learn to notice the difference between the strength zones. The outer regions of the branches on the tree will most likely be stronger than the inner parts. This is easy to see if you examine the longer needles and the healthier growth of the shoots, etc. So, now that you know how to differentiate the strong parts from the weak ones, what do you do?

Pinching can be accomplished with thumb and forefinger as shown

With candle pinching we take the first step in balancing the new growth! By pinching the candles in the strong zones in springtime by 2/3,and up to 3/4, of their length (depending on the strength of the candle). This pinching is easily done with the nails of your thumb and index finger (see drawing). By doing this we considerably slow down the growth of those stronger candles! So if all goes well this year, next year you already have to do much less spring pinching because the balance of tree will already be much improved! Remember: only candle pinch strong candles, and leave the weak ones alone, even in the strong zone!

The exact timing for removing the candles is crucial for the result we're after! If you remove them too early in the season, they will not yet have grown enough to achieve the result you want. As a result, the new buds will grow back too strongly. If you remove them too late, the new buds will grow back irregularly, some weak and some strong. They also will have a too short growing season ahead of them. So, when is the right time for candle removing? Well, you will actually learn this from directly observing your tree, but as a rule you can say that the right time is when the needles on the new candles are opening out, and start feeling a bit harder when you touch them.

• When this time has arrived, we first remove the complete candles from the middle zone with a sharp and clean shear.

• After 10 to 14 days (depending on how warm it is where you live) you remove the complete candles from the strong zone.
• Do not touch the weak candles!
  

Pinching can be accomplished with thumb and forefinger as shown

Because the tree is in the middle of its growing season, it will respond quickly with an abundance of new buds around the wound left from removing the candle; again depending on where you live this will happen in between 2 and 4 weeks. And because we have given the weak zones a big head start on the strong zones, we have balanced the energy distribution to the different zones a great deal already!

Tip: Cut the candles as straight as possible just above last year's needles (see drawing), if your cut is not straight, the new buds will be of differing strength!

Bud Selection

Later, when the new buds have swollen enough, remove some buds very carefully without damaging the buds you want to leave! Leave two strong buds on the shoots of middle strength, and two weak buds on the strong shoots! By doing so we have balanced even more the energy distribution through the entire tree! And you will see that next year the tree will need much less work to maintain its balance.

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Plucking needles is the last main task of this growing season, if this task is not done, all the previous work will have been for nothing. Fewer needles means less energy transport to the shoots!

• So, in the Fall we pluck away all the old needles to let in light and air to the inner weaker parts of the tree. Try to pluck the needles off in the direction they are growing, then there is less chance of damaging the bark. I actually prefer to cut those old needles away with the help of a sharp and clean shear just above the sheath that holds the needle bundle. My experience is that leaving those sheaths promotes more back budding than if you pluck out the needles, which will often damage them. The little stumps you leave by cutting don't look very appealing, but they will fall off eventually and in this early stage of the development of the tree you should not let its appearance concern you too much.
• At the end of the Fall, pluck away needles from this year's growth on the strong shoots, leaving 5-6 needles pairs.
• Do the same two weeks later on the shoots of medium strength, leaving 8-10 pair of needles. Again do not touch the weak shoots!

Needle plucking is stressful for the tree, so should only be done if the tree is healthy! As before, with all the other techniques described here, look carefully at what you are doing, comparing one shoot to another! Think about what you are planning to do step by step, and remember or write down what you did and take photos, so you know next year if what you did was right, or if you should change anything!

Tip: When you start working on a Japanese Black Pine there might be a great difference between the middle zones and the strong zones; in that case, you can also combine candle cutting with needle plucking. When you remove the candles from the middle zone, you also remove needles from the strong zones! This will slow down the growth off the strong shoots even more! If all goes well, this is only necessary in the first year of working on the tree. The next year the difference between the zones will be much less obvious.

Depending on the variety, you may also remove needles on a Scots Pine by hand, but once again: only if it does not leave any wounds! If pulling needles does tear the bark, be sure to use shears! On Mugo Pine you never pluck needles! Not even last year's needles! You always cut them with scissors, leaving the sheaths intact so you don't damage the dormant buds that will appear from them! By doing it this way there will be much more back budding among those needle stumps you left! Even among last year's needle stumps, because they are still receiving energy before they dry out!

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Japanese Black Pine are much stronger than the Japanese White Pine and the Black Pine will react very well to pruning, even hard pruning, when this is done in late Fall/ early Winter. It will even react with back budding on older branches.

• Prune away all the growth you don’t need in the strong zones, but be careful with what you prune in the weaker zones! When you prune away a thick branch, it is always better to leave a stump so that it has the chance to dry back naturally. That way, the tree has time to find a new path around this large new interruption. This way there is less risk of losing a branch (or worse) right above the branch you cut off.
• After the stump has dried out you can always use it as a jin or remove it entirely, if you decide to remove it you can carve it and the wound will heal up more naturally! Again only perform this heavy branch pruning on a healthy tree, and even then, not every year!

Fertilization is very personal, but this is what and how I feed my Pines. Feeding especially counts with your bonsai; look carefully at how your bonsai reacts to feeding, and when, what and how much nourishment you provide it!

• I start the feeding cycle in early spring with a very mild foliar fertilizer based on algae. When the temperature gets a bit higher I give a feeding of water-soluble liquid fertilizer. Unlike solid fertilizer that only is useful if the ground temparature is above about 17 degrees, this liquid fertilizer will get in the tree's system even at lower temperatures.
• When the temperature stays high enough for a long period and before the buds start growing too strong, I will give a feeding of water soluble "Super Bio Gold". During the period of growth of the candles I don't feed at all, except if it's a tree in the early stage of training and needs growth.

• In early Summer after candle cutting, I give organic fertilizer. During the hottest weather of summer I don't feed at all: I will start feeding again after summer when pines start their second flush of growth. The roots, especially, will grow a lot during this time! That's why this is also a good time to collect or repot pines; they only need to be protected from strong sun for a couple of weeks and given frost protection during the winter period.
• During the Fall I feed two to three times with nitrogen-free, water-soluble fertilizer (PK fertilizer).
• During the whole growing season, and even in Winter, I spray the needles and bark with products based on algae and mineral oil, that are specially developed for bonsai by bonsai professionals. I have good results with these "Sumo Bonsai" products and with their mild bonsai fertilizer.

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I use a mixture of Akadama , Kiryu, Bims (a porous lava stone product) and Japanese split (sharp split). With Mugo Pine I add even more Bims to this mixture, because of its capability to retain water without becoming sticky or losing its shape! (The soil stays loose and porous). I also add pine litter (compost) to the mixture to promote the growth of mycorrhizal fungi, which all pines need for their survival. This mixture is fine for me because I live in Northwest Europe where it rains a lot, so I need this kind of soil structure. I am also in a position to water the trees when it is very hot, sometimes even twice a day! (What I am trying to say is that you must adjust the soil mixture to your own weather conditions! With the help of some local knowledgeable bonsai enthusiast, this should be no problem.

Do not let pines dry out completely trying to reduce needle length; you will get those from using the proper techniques I explained! And when you water: water thoroughly! With the mixture I use there is almost no way you can overwater the tree. But don't let your pines stay too wet for too long; when it rains for days on end, tilt them to one side with a piece of wood underneath one side, so the excess water can run out of the soil. Even better: put them under some shelter or cover them up with a plastic sheet. Also, you must remove all solid fertilizer cakes from the soil surface when it rains for a long time, to prevent root burn! Japanese White Pines are especially prone to this.

This is best done from Fall to early Winter when we have plucked and thinned out the tree. You can get a better view of what you are doing, and there is less change of damaging the new buds.

• Be sure to check wires frequently, especially on young and rapidly-growing pines.
• With Japanese Black Pine you can wire the branch tips out level with the ground because the tree is strong enough to force the new bud growth upright, but with Japanese White Pine, be sure to turn the very tips upright.

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I always give my pines exposure to a period of frost. This way the tree knows it is time to prepare for winter. I keep them as long as possible in the open air but when the temperatures drop below freezing, I will put them in a plastic greenhouse where the temperature never drops below 0 degrees Celsius (32F). During the daytime, if the weather allows it, you must ventilate as much as possible, and be careful that the temperature does not rise too much when the sun hits your winter shelter.

Compared to two-needle Pines the Japanese White Pine is weaker and less vigorous, and overall more difficult to maintain healthy in our wet northern European climate. But again: with the right techniques performed at the right time, good results are within anybody’s reach! As with the Japanese Black Pine, management is all about redistributing the energy from the stronger zones to the weaker zones! If these annual tasks are not performed, then the strong zones will get stronger and the weak, inner growth will eventually disappear. Losing the inner growth on a Japanese White Pine can be disastrous to your tree and its future design, because even with the right techniques there will be almost no back budding! So if you lose the inner shoots they are probably gone forever!

NO NEVER! Because they are not that vigorous, if you do remove the whole candles on a White Pine, chances are you never get any buds back, resulting in the loss of that shoot and even the whole branch!

Instead of removing entire candles, we will only pinch a part off, accordingly to the strength of the candle.

• First you pinch off 2/3 of the strong candles
• 7 to 10 days later (depending on the pine growth rate where you live), we pinch off 1/2 off the candles in the medium zone.
• Do not touch the weak candles so they can gain strength!

When the tree is more balanced next year you will notice there is much less strength difference between the zones, so in following years you can pinch 2/3 up to 1/2 of every candle. When you work on an immature White Pine and you need growth and length, you only pinch back a little of the strongest candles. Never pinch weak candles, not even in the strong zones!

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This timing is very important; if you wait too long the candle has grown too much and you will damage the already opened needles. The best time to pinch is just before the needles are opening up from the candles. So, although with slightly different techniques than on two-needle Pines, the things we are after are just the same! We want to control and rebalance the growing force of the whole tree. By helping the weaker candles grow stronger and slowing down the stronger candles, they whole tree becomes more balanced!

Do this with the nails of your thumb and index finger as straight as possible, if you don’t do it straight, there will be a difference in strength in the new buds that will cluster around the spot where you have pinched the candle!

Shoot pruning is done on candles that have opened up and became shoots because they were left untouched earlier in the season, or on shoots that have grown out of the desired silhouette. Cut them back with a sharp shear, leaving 4 or 5 clusters of needles on every shoot. Don’t cut them back without leaving any needles on them, because you might not get any buds back and you will loose that shoot! Pruning shoots is only performed when shoots were left growing, in order to thicken a branch, or when they were overlooked during candle pinching. Sometimes it is good to let candles grow into shoots during the early years of developing a young White Pine; young trees react very well to shoot pruning, and will make more new buds this way because there is a lot of energy going through those freely growing branches.

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In early fall we start removing last year's needles, if we try to do this by hand we will damage the soft bark, which causes bleeding, and those wounded small branches often die back. Instead we are going to use shears to cut off last year's needles a few millimeters above the sheaths. These stumps will dry back fast and fall off.

• On strong shoots you cut off all of last years growth, if there is a great difference between strong and weak shoots you can even cut away 25% of this year’s growth.
• On medium strength shoots you cut away 75% of last years needles, they will fall off later or can be removed before spring.
• Weaker shoots are left alone! The old needles will fall off by themselves.

If you want a branch to grow, leave the buds as they are! If you want to control the growth energy, you must carefully remove all the buds but two, on the strong shoots. On medium shoots you remove the weak buds, leaving two. Again: don’t touch the weak shoots!

• Timing the Repotting: as with all my pines, I repot in spring just before the buds start to swell.
• What to Prune: be careful with root pruning. Long and fat roots are useless and should be cut back to the point where there are healthy feeder roots. Doing this will redirect the energy flow and the tree will react by making additional feeder roots, just as cutting a branch promotes the development of small twigs. So leave a greater proportion of the yellow/white tipped feeder roots.

• Cutting large roots can be done in several repotting sessions, so the thick root can grow more of those all-important feeder roots. Then you can safely cut it back even further the next time it is repotted. Take your time, especially with the Japanese White Pine! All this will result in a compact root system, full of feeder roots.

Most imported White Pines are with a Japanese Black Pine rootstock, Those Black Pine roots are used as a base because they are much stronger and therefore grow much faster. These White Pines with Black Pine rootstock are more tolerant of repotting and root pruning than field grown Japanese White Pines on their own roots. If you have one of these trees on its own roots, take extra care when you work on the roots! Never take off too much root!

• Soils for Japanese White Pine: I use the same soil as with my other Pines, but I add some more Japanese Split so the water runs through the soil even faster.
• Frequency of Repotting: Don’t repot any pine too frequently, especially the White Pine is not a fan of repotting! If a Pine is potted in good soil, once every 3 years is more than enough. If the Pine is more established, once every 5 years is even better! You must remember than every time you repot a bonsai, you will rejuvenate it and it will (after a period of standing still and recovering) react with a lot of root growth, and this will cause the new candles to grow too strongly and irregularly again! So the cycle of balancing the energy of the tree starts all over again. This is an especially important point to consider when you plan to show your Pine bonsai in its best condition! (Well balanced small needles all over the tree and a mature looking ground cover.)
• Innoculation with Mycorrhizae: Always mix a portion of your old soil medium into the new mix, this old soil is full of important Mycorrhizal fungi that the Pine needs for its survival. Remember that if you don’t put this in, that it can take up to 2 years before there is enough new Mycorrhizal fungi in your fresh soil mix for the Pine to be happy again!
• Watering after you Repot: Keep in mind that a freshly repotted tree uses less water, so let them become a bit dry before you water them generously!

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Spring branch pruning, is once again a technique to rebalance the energy flow among the shoots and small branches. If you cut back a strong branch right up next to where there is a smaller one, you will redirect the energy flow to that weaker branch. Always look at the direction that you want that new branch to grow: if it is growing in the wrong direction you must choose to cut above another small branch that does grow in the right direction. In the Fall, you can look at the whole tree and prune out unnecessary branches in all the zones. But once again think about what you’re doing: the tree must be healthy and don’t cut off to many branches at once!

Fertilization is more or less the same as for other Pines. But be careful to prevent rootburn: don’t fertilize dry soil and take off solid cakes when it rains for a long period off time. Especially because Japanese White Pines have tender roots that burn easily!

Water when the soil is dry (but not bone dry!) Try to keep the tree a little bit on the dry side during the growth of the candles, and don’t mist them too much as well, to prevent them from growing too much. But do not let the tree stay too dry for too long! This is bad for the tree and ruins the soil structure as well!

Note: I think that the Japanese White Pine, especially the field grown ones are not the best choice for novices.

So, there you have it! I know this is just a basic overview of Pine maintenance, but I still hope it will help you to take proper care of your own pine bonsai. If you have any questions, feel free to ask them.

The End.