Selecting material for bonsai part I
There are a number of ways material for bonsai can be acquired and the following sources can be a good way to start.
Nurseries or garden centres
Seed and cuttings
Before we discuss the above sources, it might be advisable to ask yourself the question –
What sort of tree am I looking for?
To assist in making the decision the following factors may be of use.
What is the climate zone – taiga, alpine, temperate or mediterranean
From where does the species of tree/plant originate – native or foreign
What environment will the tree/plant be kept in – inside or outside
If inside how much natural light will the tree/plant receive
If outside what protection can be given to the tree/plant in cold temperatures
What are the characteristics of the tree/plant – prolific or slow growing
Do I have the space and the time to care for it
These questions are important, because they are related to the health and development of a potential bonsai. For those wanting trees/plants destined for indoor propagation, there are an assortment of species available for example, Ficus of which there are many varieties. Alternatively, those with a desire for hardy coniferous and northern European deciduous species, these have to remain outside because they require a period of dormancy, (Autumn to spring) and may need additional protection during the winter months.
Reputable dealers – are able to offer a wide variety of potential bonsai to customers, but they can be expensive due to their stage of development. Such material can be had by visiting the grower’s establishment and selecting a specimen. Arguably this is the best approach, because not only does it allow you to view what is on offer, the grower will be able to provide information and advice on how to care for the tree/plant.
But not everyone is able to make such visits because of invalidity, distance and mobility therefore, they resort to ‘on-line’ purchasing.
However, not having gone down this route to obtain specimens, obvious questions abound. For example, a tree/plant may have the appearance of health and vigour. But it has to travel from one destination to another and how it fares during this transition remains to be seen. Arguably much has to do with packaging and transport and even if well protected there is still the danger of irreparable damage.
Evidence of this comes from visiting horticulture establishments and witnessing the conditions trees and other plants have had to endure during transport, then being unpacked ready for sale. However, there are those having had successful ‘on-line’ purchases will state that this scepticism is unfounded. Because growers need to maintain good relationship with their buyers; hence their stock is always in good condition. But we are not discussing house or garden plants, we are discussing bonsai that can be expensive. ‘On-line’ purchasing is a risk and one has to ask many questions before making the final decision.
Nurseries or garden centres – can be seen as a relatively good source for potential bonsai material however, it pays to examine the specimen closely. First examine the base of the trunk to determine any nebari (Surface root system) and to check how long it has been in it’s container. The obvious signs are a coating of moss on the top of the soil and roots protruding from the base. These are indications that the specimen is established in the container, further proof can be had by easing the plant gently out to further inspect the root ball. The next step is to examine the trunk for movement meaning does the trunk curve or lean to one side, and what of the branch configuration – in other words does the specimen have the potential to become a bonsai.
In addition, it pays to be diligent when examining material, because one can find lots of problems. Damaged branches, leaf yellowing caused by either over or under watering and disease. Long thin shoots with nodes spaced too far apart caused by insufficient natural light that are of little use in a potential design. A partially decayed root ball will often be a thick tangled mass that has wound itself around the container searching for nutrients that are not there; and with trees in this condition it is best to walk away.
Nonetheless, specimens with potential can be found relatively cheaply. One I found a Forsythia a member of the Oleaceae (olive family) with a good strong weathered trunk has the potential to become a Mame bonsai in a few years time. Another example was located in a supermarket of all places, the plant a Ficus microcarpa ginseng had no real potential as a bonsai. But was ideal for cuttings that when rooted could be given to bonsai students to practice on. Therefore, it does pay to browse around to see what is available.
Seed and cuttings – can be purchased from reputable distributors, but it is advisable to ask whether they have undergone the stratification period. Stratification is the process of treating stored or collected seeds prior to sowing to simulate natural winter conditions, which the a seed must endure before germination. Some seed species undergo an embryonic dormancy phase, and generally will not sprout until this dormancy is broken. The time taken to stratify seeds depends on species and conditions; though in many cases two months is sufficient. If collected seeds need stratification, they can be put in a plastic bag and stored in the refrigerator for this period of time.
Of course some species of tree especially fruit bearing do not require stratification and can be sown after the fruit has been consumed such varieties are citrus species family Rutaceae, mango genus Mangifera, avacado genus persea and pomegranate Punica granatum. However, not all seeds will germinate for example, certain apple varieties Malus, peach Prunus persica and cherry Prunus cerasus have problems. Arguably because the fruit was picked long before the much needed information required for germination could be passed from the parent plant; thus the seeds are sterile. Nonetheless, if fruiting varieties are favoured, the best time to collect their seeds is when the fruit has fallen from the tree.
Growing from seed is often rewarding because, it affords the bonsai artist complete freedom in shaping the tree’s design. But the downside of growing from seed is the length of time the plant needs to grow to an acceptable size for a bonsai potential, which can take a minimum of 5 years. Although much depends on the species of tree/plant and its characteristics. Moreover, such young specimens need to be grown in preferably the ground or large containers to allow for root run and trunk development. Because a tree/plant with a trunk as thick as a pencil will never gain any trunk girth if it is in a small container.
Cuttings also known as striking or cloning, is a technique for vegetatively (asexually) propagating plants. In which a piece of the stem or root of the source plant is placed in a suitable medium such as moist soils, a potting mix, coir, rock wool or water. The cutting produces new roots and stems and thus becomes a new plant independent of the parent.
Cuttings can be taken from soft green or semi-ripe wood and hard wood which has specific differences in practice. For favourable outcomes timing, size, location on the plant, and amount of foliage are all important factors to consider. In temperate climates stem cuttings of young wood need to be taken in the spring from upper branches. As opposed to hardened wood, which needs to be taken in winter from the lower branches. The common practice on stem cutting lengths are between 5–15cm for soft wood and between 20–25cm for hard wood. Soft wood cuttings do best with approximately two thirds of the foliage removed, whilst hard wood cuttings need complete foliage removal.
Cuttings require a humid environment either by placing them in a propagator or plastic bag or in another confined space, where the air can be kept moist and partial shade is advisable to prevent the cutting/s from drying out. Cuttings in the medium are usually watered with a fine mist spray to avoid disturbing plants. The aim to keep the soil moist but not wet and the medium is allowed to almost dry out before misting again. A rooting hormone can be used to encourage growth and maturity in plants although it is not essential. Some cuttings will grow if simply placed in a jar of water, but the water needs to be changed on a weekly basis to prevent stagnation.
Grafting – is a horticultural technique where tissues from one plant are inserted into those of another so that the two sets of vascular tissues may join together. This vascular joining is called inosculation. In most cases, one plant is selected for its good roots called the stock or root stock, the other plant is selected for its stem, leaves, flowers and fruits and is called the scion. The scion contains the desired genes to be duplicated in future production by the stock/scion plant.
In Japan this technique is most common especially with pines, such as the black, red and white species. The black pine found at low altitude is selected as the stock because of its potential for strong growth, the red pine from higher altitudes can also be used as stock material, but lacks the vigour of the black pine. At more higher altitudes the white pines are found, these have fine delicate foliage and are used as the scion and often grafted onto black pine root stock.
For successful grafting to take place, the vascular cambium tissues of the stock and scion plants must be placed in contact with each other. And both tissues must be kept alive until the graft has ‘taken’, usually a period of a few weeks. As there are many different types of grafting and much literature and audio visual presentations (Youtube) available, only one will be discussed here.
T. graft or cleft – is a common method used in bonsai where an insertion with a sharp knife is made into the stock. A vertical cut is first made followed by a horizontal at the top of the vertical cut allowing the bark to be peeled back revealing the cambium layer. The scion has it’s bark carefully removed showing the cambium still attached to the scion, which is then inserted into the stock making sure that the cambiums of both stock and scion are married together. Tape and or raffia is the wound around the join to ensure good bondage and to protect it from disease. The following illustration show this particular method.
In the next episode (Selecting material for bonsai part II) we consider Air-layering and collecting from the wild. Until then, BW, N.