Updated: Jan 7
When we work with Japanese Black Pine there are few techniques that we apply to this species but the timing that we do them has to be spot on. Although there is 1 technique that can be performed any time of the year but you still need to do it at an optimal time, and that is Needle Plucking.
First of all we need to understand why we needle pluck. Needle plucking on Japanese Black Pine is in simple terms energy distribution. When we leave lots of needles on some branches while others have few needles the branches with lots of needles will continue to get stronger and thicker while the branches with less needles will get weaker and possibly die. This becomes an issue on Black Pine due to the fact most of the time the tree favour's the top branches and we end up with big thick branches all over the top of our tree. Left long enough this can cause some bad reverse taper, couple that with leaving whorl growth on the tree and you will have knuckles on your tree.
So how do we avoid this? A technique called needle plucking.
When we needle pluck the first thing we look for is our weakest significant branch, this is the branch that has the lowest needle count but is actually apart of the trees structure and design. We don't want to pluck back to the actual weakest branch because that might be a really weak branch that we are going to cut off that only has 4-6 pairs of needles, if we took every branch on the whole tree back to 4-6 pairs of needles the tree would be in a world of hurt and in the danger zone. If your weakest significant branch is under 8 pairs of needles don't take any of the other branches under 8 pairs. 8-10 pairs of needles is a good threshold. so if your weakest significant branch has 6 or 7 pairs i would suggest taking everything else back to 8-10 pairs. ( don't count the needles otherwise you will be there all day, you can roughly eye ball how many sets of needles are on each branch and you can see they are roughly even ).
A few tips when needle plucking is always pluck your vertical needles first meaning the needles running along the tops of branches and needles running along the bottoms of branches. Try to leave some older needles down the branch and try to stagger them like they are an alternate leaf pattern. Your chances of getting back budding where old needles exist is much higher then the spot where they don't exist so sometimes you can guide where you might want back buds by leaving old sets of needles. This is a major reason why we pluck tops and bottoms first as we don't want buds on the tops or bottoms and on the off chance that there is only 8-10 pairs left after removing the tops and bottoms at least you are left with the side needles. This is a rare case though.
As mentioned earlier needle plucking can be carried out any time of year and is usually the first thing you will do when acquiring a new black pine. Remember the 2 laws of black pine, The energy is in the roots and the energy is distributed through needle mass. Knowing this will help you develop and refine your tree.
Before i go i just want to throw an extra tip out there, always make sure you have light entering every part of your tree and light is available to any needles you leave on the tree, this is especially true if you are trying to encourage back budding. If you have a section of the tree that is shaded and has low wind flow you have dramatically reduced your chances of back budding. If you can open your tree up to light and air flow you wont be able to stop it from growing!
I hope this has shed some light on needle plucking for you. We will go over the 2 other techniques which is performed on pines later but they are De-candling and Bud Selection.
Until Next Time, Enjoy Your Bonsai Journey