Hard Pruning/ Removing Branches
Pruning of branches is nearly always carried out when the trees' growth slows down in late
Autumn through to Spring to avoid excessive sap-loss. When pruning in Winter it is always best to leave a small stub rather
than cut back close to the trunk. Leaving a stub when pruning pines is advantageous as it leaves open the opportunity in the
future of creating jins and it also allows time for the sap-flow to bypass the missing branch, reducing sap-loss through bleeding.
Pruning close to the trunk and hollowing out is best carried out whilst still semi-dormant in early Spring as scars will heal
quickest with the Spring growth that follows.
It is better to be conservative when hard-pruning and reducing Pines.
Severe reduction without allowing for recovery time can be fatal particularly with old or large trees. Reduce large trunks
and/or branches gradually over a number of seasons so that the tree is able to adjust.
Needle plucking is a very useful tool for pine maintenance. It allows air and light to penetrate the outer foliage
to increase the health and vigour of inner shoots and branches. It also helps to spread energy throughout the tree in the
same way that bud selection and candle pinching do.
In late Autumn or early Winter, both old and new needles are plucked
according to their position on the tree. The principal behind needle plucking is that the more foliage or needles a branch
has, the more vigorous it is; by reducing the amount of needles on a vigorous area of the tree (such as the apex) in comparison
to the number of needles a weak area has, vigour is distributed more evenly.
From left to right
Image 1: Lower or inner shoot
Image 2: Mid-level shoot
Image 3: Upper or Outer shoot
a basic rule leave less needle-pairs on the upper shoots and more on the weaker, lower and inner shoots. Often no needles
are plucked from inner shoots to preserve their vigour. The actual numbers of needles that are removed will depend on the
needs and strength of the tree. With a very vigorous tree it may be possible to leave as little as 4 pairs of needles on the
upper branches, 6 or 7 pairs on the mid-level branches and 8-12 on the lower branches. Base your starting number on the lowest,
weakest shoots since you can only decrease strength with this technique and not increase it. Do not remove so many needles
that the overall vigour of the tree or branch is lost.
Shoot Trimming and Forcing Back-Budding
To force a Pine to back-bud is difficult ordinarily. However, shoot trimming is a useful technique
for trying to force back budding and generally increasing the number of buds on a tree.
All shoots should be allowed
to grow unhindered throughout the growing season. In Autumn, all the current years' growth is removed leaving only the previous
years needles. This will cause the tree to produce a large number of buds at branch tips and further back along the branches,
sometimes even into old wood. This technique is however very stressful for the tree and should only be carried out on healthy,
The development of foliage
pads or branch structure on a bonsai dictates that the branch tips should fork and sub-divide into only two smaller sub-branches.
As previously stated, Pine buds most often emerge in clusters or whorls at the end of branch tips. The basic rule in Bud Selection
is to select two of the buds and remove the rest so that when the buds extend as shoots they form a two-pronged fork.
From Left to Right;
Image 1: Example of a typical bud-cluster
Image 2: A cluster in a dominant area should be
reduced to two weak buds
Image 3: A cluster in a weaker area should be reduced to 2 or 3 stronger buds
Buds continually need to be reduced to two as they appear, in Autumn and in Spring. Deciding
which 2 buds in a bud cluster should be retained needs some consideration. As previously stated pines are apically dominant,
upper and outer areas can (and should) be restrained by careful bud selection and elimination. Apical areas of a pine can
produce 5 or more buds to a shoot terminal, by removing the largest and strongest buds and retaining the two smallest and
weakest, vigour is re-directed to wards inner and lower areas of the tree. Conversely, weaker lower branches are allowed to
retain their largest, most vigorous two or three buds to encourage more vigour to them. If a third bud is retained on a weak
branch it can be removed at a later date when its job is done.
To encourage good branch structure and proper formation
of foliage pads, whenever possible, buds that appear on the sides of a shoot should be retained rather than those than on
top or below.
From left to right;
Image 1: Appearance of shoot tip before bud selection in Spring.
2: After bud selection.
Image 3: After extension of the buds into new sub-branches in Summer. Note the appearance of a
further set of buds developing at the new shoot-tips.
During the Spring, the buds that you have retained will elongate into candles, their size being in relation
to each candle's individual strength and vigour. To ensure that growth extension is regulated and energy is dispersed evenly
throughout the whole tree; these candles need to be pinched back. The amount that each candle is reduced depends on its position
within the structure of the tree and its future purpose. After the candles have extended into new shoots and branches, it
is at their tips that new buds for next year will form.
Just as in bud selection, candles growing in more vigorous
areas of the tree should be reduced by far more than candles growing in weaker, inner areas. If a new branch or sub-branch
is required the candle can be left unpruned to extend; however it should be noted that more of the trees energy will be directed
to it at the expense of other areas. Candles left unpruned to encourage vigour in weak areas or to develop new branches can
then be cut back to a desirable length once they have fully elongated and hardened, this will soon be followed by the appearance
of buds at the tip.
The timing of pinching out candles will affect where the new buds that follow will form. Pinching
the candles before the new needles appear will cause new needles to form at the base of the candle. Pinching the candles after
the needles begin to appear and start to elongate will cause the buds that follow to form at the end of the new shoot.
pinch out all the candles at once. Start pinching out the weaker areas of the tree first and finish with the strongest areas
2-3 weeks later. Generally, as a rule of thumb, candles growing in vigorous areas of a Pine should be reduced by at least
1/2 to 2/3, candles in weak areas should be reduced by no more than a 1/3.
It is often necessary with all but the largest Pine bonsai to reduce the length of the needles
to help refine the image of the tree.
It has often been that recommended that needle reduction can be achieved by reducing
the amount of water and fertiliser available to the tree during the Spring so that new needle growth is limited; literally
'starving' the tree. This is not a satisfactory technique as it entails deliberately weakening the tree and reducing its vigour
for a number of weeks.
These days, there is a new technique which helps reduce the length of needles by limiting the
time the tree has to grow it needles before growth slows or stops for the Winter.
Allow shoots to grow through the
Spring and Summer. In mid-Summer, cut the new shoots leaving only last year's needles. Over the course of the next few weeks
new buds will form; these will need to be reduced to two as outlined previously. These new buds will not develop into candles,
but will sprout new needles as soon as possible. They will not have enough time in the remainder of the season to grow long
resulting in a set of reduced needles.
From left to right:
Image 1: Two candles that have been allowed to fully extend into shoots.
Image 2: After trimming
back in Summer
Image 3: Resulting buds.
This technique should only be carried out on Pines that have an established trunk
and branch structure. Using this technique will decrease the vigour of the tree and its ability to thicken up branches and
trunks; needle reduction should be regarded as the last stage of developing a pine bonsai.