Wee Trees Bonsai Help Forum Advice for all

Thread Grafting

A virtually fool-proof method for adding new branches and roots

THIS IS THE only method of grafting that I would recommend to amateurs, simply because it's the only one I've ever done successfully every time. In fact, thread grafting is virtually fool-proof and success is almost guaranteed ... in time.

Thread grafting is ideal for creating branches or roots at the precise point where they are needed to complete or improve the design.

The technique itself couldn't be simpler.



Grafting branches

Grafting can be done any time between early spring and mid-summer, and will take between one and three years to work, depending on the vigour of the tree.

First you need to allow some shoots to grow freely until they are long enough to be bent around to cross the trunk at the point where the new branch is needed or alternatively use a sapling which can remain in its pot beside the recipient.
Then you drill a hole straight through the trunk at the point where the branch is to be grafted. Start at the side where you want the branch is to emerge (this ensures the cleanest edge to the hole on that side of the trunk)
Take a convenient shoot and carefully CUT off all the leaves very close to the shoot. Don't pull them off or you will damage the axillary buds.
Bend the shoot and push it through the hole as far as it will go without breaking or until it makes a tight fit.
Tape or wire the shoot into place, seal the edges of the wound and wait....
... When the shoot, or new branch, becomes much thicker on the side it emerges than on the side where it enters the trunk, it is a sign that the graft has "taken".
Wait one more year before severing the branch on the insertion side - just to be on the safe side. If the shoot is on its own roots in a pot, this must be watered and fed as usual.
That's really all there is to it. As the shoot thickens and the wound begins to heal, the two are forced together with such pressure that a natural graft occurs. There's no need to expose the cambium on the inserted shoot or to get up to any other fancy tricks - just let nature take its course.

Be very careful when wiring new grafts because, remember, they are only held in place by a very thin layer of new tissue and will easily come away. As time passes they will become much more robust.



Grafting roots

The principle of thread grafting new roots is precisely the same as for branches, except that when the graft has taken, you retain the "parent" part, and discard the other. Best time for this operation is early spring, before the buds open, but it can be done with care any time during spring/early summer.

Find a healthy seedling of the same or closely similar variety as the main tree. The stem of the seedling must be roughly the same thickness as the existing surface roots on the main tree.
Drill the hole at an angle sloping upward from the exact point where you require the new root.
Excavate a wedge of soil in the pot to accommodate the roots of the seedling.
Prune all lateral branches and leaves off the seedling and push it up through the hole, making as tight a fit as possible.
Gently arrange the roots in the excavated space and refill with soil. Water thoroughly and keep the assembly in the shade for a few weeks.
Feed the tree well to encourage rapid thickening of the inserted stem and healing of the wound.
Always wait a season longer than you think is necessary before cutting off the free-growing top of the inserted stem, leaving the trunk base and roots behind.


Addendum
Seal the open ends of the hole after inserting the thread with grafting paste or your usual sealant to conserve moisture.

_________________
My name is Don and I'm a bonsaiholic
'in arduus nakarus' 'ad sum ard labor' 'in vino veritas'



Success in bonsai consists of moving from failure to failure without loss of enthusiasm.
(Misquotation of Winston Churchill's words)


Bonsai limbs are held
In copper-wrapped attention --
Worth their weight in gold.

WATERING


I have stated ad-nauseum that sufficient water should be added to the planting medium of a potted plant/tree to maintain a just moist consistency. Neither too wet nor too dry. This is not the full picture of watering requirements.
Water is needed for the metabolism of a plant to continue to work. Water pressure in the plant system is necessary for it to hold its leaves and twigs up without drooping. It always moves toward the highest concentration of salt so if the planting medium contains more salt than the top of the plant, water will be drawn downwards instead of up and the plant will probably expire.
Photosynthesis in the leaves converts carbon dioxide and water into sugar and oxygen. Water then, is again necessary for that procedure to take place.
As the weather becomes warmer, the leaves transpire (their equivalent of sweating) to keep the plant cool, making a larger amount of water necessary and this has to be taken into account.
Ideally the water should contain little or no salt and have a pH value of something between 6 and 7.5.
Hard water has a high carbonate and/or salt content, some of which can be reduced by drawing the mains water and allowing it to stand for a time, when some of these, particularly chlorine, will be released into the atmosphere. The standing water will also assume the same temperature as the air and will benefit from being close to the plants/trees for which it is intended.
Pond and well water can often have concentrations of salt in it and should only be used if tested and found suitable.
Rain-water appears to be the best for our purpose if it is collected and stored out of contact with contaminants. It is usually almost salt and calcium free and very slightly acidic. It is nearly mandatory for Rhododendrons, Azaleas, Camellias and Gardenias.
If you grow Hornbeam, Hazel, Hawthorn, Beech, Spruce, Yew or Cherry be particularly careful about avoiding salt.
A modicum of lime is welcomed by Euonymus, Sabina juniper, Apple and pear, Blackthorn, Oak, Mountain ash Beech and Yew.
Watering through a fine rose gives a more natural application and is less likely to wash medium out of the pot or cause puddling. Leaves may also be wet in this way but not if watering last thing before nightfall when less evaporation takes place. Moisture remaining on the leaves overnight or for a long time can result in fungus growth.
Only if the root ball has dried out completely, it is sometimes necessary to dunk the pot completely in water until all bubbles cease to rise. Peat based mixes are sometimes difficult to re-wet and may need this and even a spot of detergent added for particularly moisture resistant mixes. After being allowed to drain, subsequent watering is best continued from above in the normal way. The passage of moisture from top to bottom of the medium draws air in behind it. Air being necessary for the health of the roots too.

_________________
My name is Don and I'm a bonsaiholic
'in arduus nakarus' 'ad sum ard labor' 'in vino veritas'



Success in bonsai consists of moving from failure to failure without loss of enthusiasm.
(Misquotation of Winston Churchill's words)


Bonsai limbs are held
In copper-wrapped attention --
Worth their weight in gold.

Wire for styling

When wire is used to reposition twigs, branches or trunks of trees with a view to improve the design, some things are best kept in mind. The thickness used should err on the larger side rather than the smaller or the holding power will be insufficient for the purpose. Progressively thinner sizes will be used as we get further away from the trunk.

When wire is in position during a period when active growth is taking place in the subject, it will not need to be in position for as long and it should be inspected frequently to ensure that it does not start to bite into the bark. This could cause unsightly grooves or scars. A secure anchorage must be the start of any wiring e.g. a couple of turns around a part of the tree, which is stronger than the part to be modified. Then the wire should contact first on the outside of intended bends before winding along the branch/twig at an angle approximating 45 degrees.

Any bends made then seem to hold better if a slight twist in the same direction as the wire route is made at the same time as the bend. Woody growth is more likely to snap when being bent and may be taken to its new position in stages with rests in between. A procedure to stop bark from being lifted as the bend is made is being used more frequently these days. This is to bind the area with soaking-wet raffia, which shrinks slightly as it dries or with some kind of tape before applying the wire. The bark is stretched on the outside of bends and compressed on the inside. The binding holds it in contact with the wood and keeps the feeding streams intact. This is not necessary when dealing with thinner, less woody areas.

Mature trees in general, have branches, which become more horizontal as they age. Their attitude is due in part to environmental influences such as wind and snow, which may bend them this or that way. What we are doing with the wire is acting like these other influences on juvenile growth to make it look older or as though it has been battered by the elements for years. Guy wires, which are sometimes anchored to the pot or a dead branch to pull part of the tree toward them, are sometimes left on for long periods. To avoid damage, the live parts in contact with the wires must be protected with something like foam or plastic sleeving which spreads the applied force over a wider area.

Behaviour of copper and aluminium wires

You may have noticed that copper, size for size, has greater holding power than aluminium when used to shape branches and twigs. This is because it hardens more when it is worked or bent. In fact the strength of copper after bending can be almost three times greater than when you start using it. To try to explain why this is we have to look at the molecular structure. It has a cubic crystal which allows for easy bending, however, as it is bent, the crystals are deformed and cling to each other more rigidly making further bending or working harder. In other words, it holds better for bonsai purposes.
Aluminium wire does have the same qualities but nowhere near as marked as the copper.
A benefit of this characteristic is that it can be reversed by the process of annealing, which brings the crystals back into their original uniform cube shape, so allowing the easy bending property to be regained. To anneal your wire for re-use, bring it up to a dull red glow and allow to cool. Bear in mind that it will scorch anything with which it comes into contact while hot, including skin, so hold it firmly in your pliers or some such incombustible tool while you heat it. I use the gas ring for annealing, which does not deposit soot on the wire like some other methods of heating.

A further point is that, particularly with the larger diameters, the mere action of uncoiling copper wire, hardens it appreciably, so if you are going to re-use a comparatively short length, keep it straight until needed.

The presence of copper in the compost slows down root extension, so if you use copper wire to hold the drainage mesh in place, your drainage holes do not get clogged up by the roots as easily.

A small contra-indication to the use of copper as opposed to aluminium is that you do not need to use such a large diameter and it is more likely to cut into the bark if left on for too long.

_________________
My name is Don and I'm a bonsaiholic
'in arduus nakarus' 'ad sum ard labor' 'in vino veritas'



Success in bonsai consists of moving from failure to failure without loss of enthusiasm.
(Misquotation of Winston Churchill's words)


Bonsai limbs are held
In copper-wrapped attention --
Worth their weight in gold.

Wrap around
further thoughts

This is a technique where an entire tree is grafted to deadwood to create an illusion of great age. Also called Tanuki.

An interesting piece of dead material is thoroughly dried and preserved. A slight channel is made following the natural grain unless a natural one exists. The live material is laid along this. The living tree is stripped down to the cambium layer along one side and this area is placed in contact with the host. Young trees are best for this as they still have small enough section to be easily pliable. Its roots should remain in the medium in which it is growing as far as possible.
To fasten the tree many options are available. You may wrap the entire thing in raffia and allow it to sit for the entire year before checking its progress. You may also use copper or brass nails or screws to fix the graft. Finally you may use cable ties padded by some material that won't rot and harm the bark or graft. The whole bundle is potted up as one tree. In a season or two the living tree should adhere to the old and become one single tree, giving the impression of an aged and weather-beaten individual. Needless to say, the normal watering needs to be attended to as usual and feeding resumed after six weeks..

_________________
My name is Don and I'm a bonsaiholic
'in arduus nakarus' 'ad sum ard labor' 'in vino veritas'



Success in bonsai consists of moving from failure to failure without loss of enthusiasm.
(Misquotation of Winston Churchill's words)


Bonsai limbs are held
In copper-wrapped attention --
Worth their weight in gold.

WIRING INTO THE POT.

Being shallow rooted by choice, bonsai do not have the long tap roots found on the trees which are growing in open ground.
They can be rocked and even blown out of the container by the wind.
A piece of wire is passed up into the medium through the drainage holes opposing each other. There will be a string of wire across the base of the pot. The two free ends are taken over the root-ball and twisted together. The twisting is continued until the tree is firmly held in place. It is usually possible to lift the tree by the trunk without the pot dropping off. Excess wire is snipped off and the twisted ends buried for the sake of aesthetics. The better class of pots will usually have several smaller holes in the base for the specific use of wiring in.
In the case of only one drainage hole being available, a piece of stronger wire or a stick may be laid across the outside of the hole and the retaining wire passed either side of it for anchorage.
All bonsai should be fastened in in this manner.

_________________
My name is Don and I'm a bonsaiholic
'in arduus nakarus' 'ad sum ard labor' 'in vino veritas'



Success in bonsai consists of moving from failure to failure without loss of enthusiasm.
(Misquotation of Winston Churchill's words)


Bonsai limbs are held
In copper-wrapped attention --
Worth their weight in gold.