This article is an update on a twin trunk Sorbus aucuparia rescued from an area of wasteland being prepared for development in early spring of 2015. The folklore and scientific information on the species can be found on this site ‘Sorbus aucuparia (Rowan or Mountain ash) October 11, 2017′ but for those whom require a brief update please continue reading.
When the plant was collected its height was in excess of 2 metres and thus had to be reduced, as the fronded-like leaves are quite large it was decided that, the plant would be suitable for the ‘Omono Dai‘ class (the first category for large bonsai trees 100 centimetres or 40 inches. 70% of the root ball was removed and the foliage was reduced to maintain a balance between the nutrients to the leaves and roots respectively. The plant was placed in a wooden box in a standard soil mix with slow release fertiliser pellets and moved a semi shade area to recover.
In the spring of 2016 it was needed to reduce both trunk’s height due to the large amount of buds that had formed, (red broken circles) hence the cuts were made from the back of the tree at an angle to hide them, these were covered with petroleum jelly (vaseline) a) to allow for moisture run off and b) to prevent possible infection from pathogens. (The visible rubber coated block of wood was placed there to keep both trunks separated, this was later replaced with a specially designed expansion clamp the article for this subject is also found here; Expansion clamp design and construction – May 15, 2019)
In spring 2017 the tree was replanted in a large modified plastic container and pruned to encourage foliage growth with the hope that leaf size reduction would occur as shown below.
As the yellow arrows show there has been a slight reduction in leaf size however, the plant did not produce any flowers nor did it in 2018, 2019 and 2020, probably due to the constant hard pruning it has received, which has set it back somewhat.
In May of this year there were cold spells with bouts of snow, hence growth has been retarded, this is the same plant in June of 2021 – leaf size has been significantly reduced and it has finally flowered top left.
As stated the growth rate has been retarded nevertheless, it is possible that flowers on this plant will be produced on the right of the two trunks, but we will have to wait until 2022 as it is too late for this season. It is now 2nd week of August and the fruit have turned orange, but we still have to be patient because they may turn red which is a useful factor in deciding on what colour of ceramic pot will do the tree justice.
Choosing the pot – In studying this twin trunk (Sokan) we see that the design is arguably reminiscent of a dancing couple (male on the left – female on the right) in graceful movement. The bark is grey, foliage is light green flowers are white and berries at this juncture are orange, this suggests that the whole combination has a light tone to the overall composition; therefore, in keeping with this theme the intended pot should reflect these factors.
According to the bonsai guide lines the tree is the picture and the pot is the frame, strong dark colours would be overpowering disrupting the overall composition of tree and pot as would an unglazed pot. Hence the decision was to go for glazed neutral white. As to the pot shape we looked at round bowls and ovals but, these taking into consideration the height of the tree would not look correct therefore, the last option was a rectangular pot.
In addition, pot depth was/is another important factor to consider, bonsai pots are classed as masculine, feminine and neutral; this twin trunk is considered to be neutral. A large deep pot although ideal for ‘root-run’ would be overbearing for this S. aucuparia, the decision was/is to opt for a shallow depth rectangular pot that would be in harmony with the tree creating a balanced composition.
Obviously the tree has to undergo more training, pruning and wiring which, takes time. A living organism such as this plant has many changes in its yearly cycle of growth, changes that cannot be disrupted we can only go with the flow as said before patience is a virtue. Nonetheless, we believe it has bonsai potential, but time will tell. Until next time BW, Nik.