This is the third part of a series of 3 articles by Walter Pall on the subject of collecting wild trees (yamadori). Originally printed in Bonsai Today #74,75 and 76, these articles fueled my own ambition to collect old, wild trees for use as bonsai. The information contained within these articles were of enormous help in not only successfully collecting and ensuring the survival of my collected trees, but also in teaching the respect necessary before one removes trees from the wild.
More of Walters work can be seen at his website http://walter-pall.de
The recently dug up tree has to be transported and given the necessary care as soon as possible. For that reason, there is no sense in converting vacations into a kind of safari in search of a tree to collect because the tree removed from the ground that does not receive the necessary care, will not likely not survive in the trunk of a car.
Once home, the best thing to do is to put the tree in a large rainwater tub. The next day the tree will be very moist and the enthusiast will have recovered his strength and will be eager to work.
The experienced bonsai collector will have determined prior to arriving home what he is going to do with the tree. For the majority of recently collected trees, the best option is to place them in a wooden box that fulfils the functions of container and will permit the tree to recover from the traumatic treatment it has undergone. To do that:
· It must be easily accessible and must not present problems for watering.
· The soil mix that you use must be permeable and must be able to retain water. Given this case, its composition should be improved by adding coarse sand and peat. It is better for the peat to be bark humus. Actually, you could prepare a mix similar to one you would use in a bonsai pot: a mixture of coarse sand, peat and humus. Somewhat coarser like that which would be used for a tree in the process of being trained, with good drainage, to avoid rotting of the roots.
· The location must be protected from the wind. A fence would be ideal, some type of wattle screening etc, placed in the direction from which the predominant winds blow.
· Place the ensemble in a shaded or semi-shaded location in order to complete the protection of the tree.
Before planting it, take advantage of a last opportunity to analyze the rootball. All roots that are clearly dead must be removed. The live roots, thin and long, must always be left even if they have wrapped several times around the rootball. These roots will nourish the tree and assure its subsistence. Cuts that are not clean and broken parts must be gone over again with very sharp pruning scissors since a smooth cut will facilitate the growth of new roots and callus formation.
The cut area must always be pointing downward. You never know if this very part of the root will someday emerge on the surface in the pot. A root with a rough cut will not do very well. Also, new roots always grow downward.
When working with roots, never consider whether the rootball will fit into a pot or not since that is not the main problem. First you must get the tree to survive and to do that it will probably be too large for any pot. After two growing periods in the wooden box, you will be able to dig the tree up again and prune the rootball more severely. Often it will be better to plant it again in the same place and leave it for one or two more years before pruning the rootball again to obtain the right size for the final pot. Do not cut off the thick roots since these roots will have importance for the tree corresponding to their diameter. It is always better to think about the method of pruning incorporating the training in it. There is always the possibility of layering.
Nick Lenz who, for many years has been working with native trees in the eastern United States, thinks that more than 50% of all trees collected do not die because the rootball is too weak, but mainly because of parasites that have been brought along with it.
The tree, having been weakened due to transplanting, is not capable of mobilising its natural defences. So, as prevention, Lenz recommends subjecting recently collected trees to a treatment with insecticides and fungicides.
He even goes so far as to put the trees in a large plastic bag so that the air will remain contaminated and will kill the last parasite, at the same time maintaining very high levels of humidity in the air. The trees are subjected to this treatment in the same place where they were found so that the parasites do not end up infecting the entire bonsai collection.
Make a hole with a shovel for placing the tree in the soil of the wooden box. The hole should be quite a bit larger than the rootball. The tree is placed in the centre, with the help of another person, if necessary, to hold it. If the tree is too large and, due to the shape of the rootball, it appears that it is not going to remain very firm, it is advisable before closing the hole to put in a strong stick to which the tree can subsequently be fastened.
The soil is usually placed over the hole. It should never be tamped down, since that would hinder the subsequent supplying of air and, also, would break some of the fine roots. Next, the rootball has to be ‘muddied’.
This means that it must be watered with special intensity so that the soil is distributed well among the roots, securing the tree in its position. Now you can proceed to water the tree, adding a growth hormone such as vitamin B2 or Super Thrive to the water.
Some authors (Peter Adams for example) explain that, before planting the rootball, they leave it an entire night in a receptacle of water to which a growth hormone has been added. Nothing will happen if, in the beginning, the level of the soil is higher around the trunk than in the rest of the box. Over the time, it will level off.
If the wooden box is in full sunlight, the crown can be covered with a shade netting that can be found in various densities in specialised gardening shops. This netting prevents drying since it will reflect more than 50% of the sun’s rays. In addition, this mesh will permit the creation of a moist microclimate that will be beneficial to the tree during the first weeks. It can also be sprayed with anti-evaporation protection as is done in greenhouses when valuable conifers are transplanted. Anti-evaporation protection is a solution that is mixed with water and applied to the needles with a sprayer. This substance creates a fine layer of wax that is not impenetrable, but that reduces evaporation notably, depending on the concentration. The film is rain-resistant, but disappears by itself after a few weeks.
As has been said, the container can be a wooden box, but also a large plastic tub, a plastic washbowl, or an extra large bonsai pot if you have one available (which would be unusual). Logically, all these receptacles must have one or, much more advisable, several holes for drainage. Some professionals insist that it is essential to have the soil sterilised.
The rootball does not have to be cut to the measurements of the container, a container must be found in which the rootball will fit. It is preferable to have the tree fit exactly in the container. It is not good if the container is too large because too much moisture will accumulate in the soil that could cause the roots to rot. The container must be strong enough to support the weight of the tree, generally large and heavy trees, together with the soil. It must also be kept in mind that almost certainly in the coming months the whole thing will have to be moved, so very large trees it is advisable for the container to have handles.
As has been said, the mix that you use now will be more permeable than the soil that will be use subsequently as bonsai soil.
Good results have been obtained with a mixture of 40% coarse sand, 30% akadama and 30% composted bark humus. Pumice stone has proved to be very efficacious as soil for the bottom of very large receptacles. It has characteristics similar to those of akadama or lava granules, but it is lighter. Many enthusiasts avoid using old soil for fear of bacteria and the remains of fertiliser. However, it is advisable to add soil from healthy trees in order to include mycorrhiza.
Immediately after planting the tree, the soil has to be watered thoroughly. Afterwards it only has to be kept relatively moist so that the roots will be stimulated to grow. On the contrary, the crown has to be sprayed with water daily to keep it always moist. In no case should fertiliser be applied before the tree shows clear signs of growing.
The container should be placed in a shady location, if possible, away from currents of air. Here it must stay until the tree shows clear signs that it has caught on.
Then it should be placed in semi-shade and, subsequently, in sunlight. It is important to protect the tree right after collecting from frosts or desiccating winds.
To do that, the ideal is to keep it in a cold greenhouse for the first year. For very valuable trees, a heating system may even be installed in the floor, a system that you can find in shops specialising in accessories for greenhouses. It appears that in Japan they even install small nozzles in the floor, under the roots, that regularly blow warm vapour on the cold roots.
Serge Clemence has developed a method with which he has succeeded in getting even trees with poor roots to catch on well. He carries a rucksack full of sphagnum moss to the spot where he found the tree. Immediately after digging it up, he wraps the rootball with the moss and ties it.
Once he arrives home, he places the tree in a receptacle just as it is and adds soil around it. He says the success is astonishing. After a growing period, the moss is full of fine roots. Even trees with fibrous roots collected from cracks in rocks, have caught on this way. With this method it would also be possible to plant trees in soil outside. Nick Lenz has developed a method for making a larch layer easily with sphagnum moss. He discovered that the layering only worked well with live sphagnum moss and thinks that it is due to some hormone. Logically, this fact would be a great endorsement for Serge Clemence’s method.
Wait at least one growing period before starting to shape the tree. It is important to make clear that you are talking about growing periods and not months. If you collect a tree in Autumn and plant it immediately in a wooden box, it may catch on that Autumn, but you have to wait until it has definitely caught on in the next Spring or Summer before starting any preparations for shaping.
If a tree was dug up in Spring, possibly the first shaping tasks can start in Autumn if it has enjoyed a Summer ‘crowned with successes’.
The Number of Growing Periods from Collected Tree to Bonsai
Old Deciduous Tree
Young Deciduous Tree
|Start of Shaping|
This table shows the timetable for a collected tree to be converted to a bonsai.
For example, for an old conifer (more than 50 years old) with a good rootball, between 3 and 7 growing periods may be necessary before being able to start shaping, while shaping itself may take between 5 and 10 periods. From the time a tree is found until the day when it can be called a bonsai, between 8 and 17 periods or, indeed, years pass. If the roots were not in an ideal condition from the beginning, the complete process may even take 11 to 22 growing periods. It is clear that shaping continues over many years.