Introduction: in most cases writing articles on bonsai normally follows the seasons as it affords those seeking information current for the time of year however, this is not always possible due to heavy work load and other commitments. This article was originally intended for September this year (2018) and is well overdue nonetheless, it may be of use to those residing in temperate zones where the weather remains clement.
For those in northern regions autumn is well and truly upon us and local nurseries or garden centres are selling their stock at reduced prices, hence it is time to hunt for those bargains. (See the article posted August 3rd 2017 Selecting material for bonsai part III)
Many trees and shrubs will show signs of fatigue or damage, but there are specimens that can be had at a good discount and having found many species over the years both coniferous and deciduous including, Picea, Abies, Ginkgo and Cotoneaster. But something different was needed to experiment with over the coming winter months, thus attention was focussed on the Japanese maple.
In July (2018) quite a few varieties of this species were available, but their cost (25 to 30€ each) did not warrant their condition; tall (80cm) straight and leggy, internodes 5cm apart with sun burnt or wind damaged foliage and saturated alkaline soil. Revisiting the store in late August 3 specimens remained and although their price had been reduced to 7€ each, they seemed beyond redemption. Nonetheless, not being one to shy away from an experiment or challenge they were purchased.
After examining the plants for any signs of disease and unwanted pests, they were placed in sheltered location away from direct sun and wind however, due to their overall condition there was no possibility of becoming potential bonsai. Mainly because the trunks and branches had lignified to a point where wiring to shape was impossible without causing severe damage. It can be argued that methods including, grooving, channeling, splitting and V notching exist in creating bends in trees, but with these young maples having trunks 1.5 to 2cm there is insufficient material to accommodate such practises.
Japanese maples are rather delicate unlike their more robust counterparts the trident maple A. buergerianum, ‘sugar maple’ A. saccharum, American ‘sycamore’ A. pseudoplatanus and ‘Norway’ maple A. platanoides, moreover, their root system is quite fragile and prone to attack from pathogens and nematodes hence, many are grafted onto hardy stock for example, A. palmatum.
Looking at these maples (1. Oridono nishiki 2. Orange dream 3. Butterfly) the plan was/is to air-layer them (often referred to as marcotting) and in so doing 3 separate plants could be had from each individual plant; the blue arrow shows one air layering success and red arrows show other air layering in process.
As these maples were grafted onto different stock, all air layering had to be above the grafted area in order for the new root system to develop and in so doing retain leaf colour and variation as shown below.
Basically when we air layer, we are just producing clones of the parent plant and in theory the process works – we get a replica, but there is always the chance of a mismatch hence, the new plant has little resemblance to the parent plant so what has happened? To fully comprehend the scientific process of cloning requires an in depth study, but it can be simplified here for the purposes of this article.
Scientists have been aware for some time that ‘clonal’ organisms known as regenerative are not always identical and some contend why this is the case. In brief the genomes of the cloned plant carry relatively high frequencies of new DNA sequence mutations that are not present in the genome of the parent or donor plant, despite the fact that they are derived from genetically identical founder cells, hence the reason for mismatch.
The air layering process on the three maple varieties has been completed and the stocks have been cut back hard below the graft and as the above images show; A. palmatum is resilient and recovers quite quickly sprouting new growth. These three plants will be allowed to recover and develop in an indoor environment under full spectrum lighting at room temperature 20c (68F) and watered with an acid solution. (7 litres of tap water with 1 level teaspoon of vinegar to reduce the alkalinity)
Another reason behind the experiment is to find out what varieties these A. palmatum root stocks are, because although (a) the growing mediums of all of these maples is the same and (b) the leaf design and structure are similar there is a difference in the colourisation as can be seen in the above images 2 green and 3 pale pink. The next article also this month will contain an update on ‘Lighting for bonsai’ so until next time, BW, N.