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  • 8/7/2019 - Bonsai GRAFTING Technique_ENGLISH.(plants-gardening-horticulture-agriculture-botany-permaculture-cooking-fo

    http:///reader/full/-bonsai-grafting-techniqueenglishplants-gardening-horticulture-agriculture-botany-permaculture-c 1/4

    Text and illustrations: Pieter den Uden

    Photography: Bonsai Europe Studio

    Its about eleven years since I was on the

    search for red flowering hawthorn

    (Crataegus oxyacantha). Most of the trees I

    found, though, were unsuitable as bonsai

    because they had a poor root base, and

    only high branches on the trunk, which also

    had no movement in it not a favourable

    scenario. So I decided to grow them

    myself, just the way I wanted

    Because of my education in horticulture, I had some

    knowledge of the art of grafting. First of all I graft-

    ed with red flowering hawthorn but, later on, I grafted

    on other deciduous and coniferous species, too. By

    experimenting and learning from experts, I managed to

    improve my technique. I will show you how I graft

    with hawthorns.

    Grafting is to place a freshly cut part of a plant in bud

    (the scion) directly on to a freshly cut trunk with a root

    ball (rootstock). The aim is to encourage both to grow

    together as a single plant. There are different methods

    of grafting for deciduous trees, but the main goal is

    that you have a rootstock and a matching scion. The

    method demonstrated here is the one I use for grafting

    hawthorn, but it can be implemented for almost any

    deciduous tree.

    Why graft?Grafting is used when plants grown from seed take too

    long to mature, dont blossom in a reasonable time,

    nor grow true to type. Pine, beech, or red hawthorn is

    difficult to propagate from cuttings. Some plant vari-

    eties simply dont have strong roots, so they are graft-

    ed on to stock that posseses this quality.

    Natural response to a cut or woundWith grafting, we make use of the healing ability of

    plants. The so-called Cambium layer helps to heal over

    cuts or other wounds. The Cambium is a one-cell layer

    that generates new tissue to transport liquids, for

    growth in girth and is situated between the sapwood,

    phloem and bark layers. Transportation of water and

    nutritious salts are to be found in the sapwood layer.

    In the phloem layer the nutritives produced by the

    leaves circulate downwards. When you graft, both the

    scion and the rootstock will develop cells that have a

    corky texture, called Callus. Under the influence of theCambium layer the callus cells will grow over the bare

    face of the wound.

    Grafting redhawthornGetting up early to

    ask the nursery-

    man if I can cut

    some shoots for

    myscions from his

    hawthorn stock

    58

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    (1) The rootstock of

    the hawthorn

    (Crataegus monogy-

    na) is selected

    according to thick-

    ness and root base.The roots are pruned

    and the trunk is cut

    very short, so that

    you can place the

    scion very close to

    the root base. As a

    result, when the

    buds sprout they will

    develop branches

    low on the trunk

    (2) Here I cut the

    root stock

    (3) Here I try to fit

    the rootstock with

    the scion of a

    Crataegus Pauls

    Scarlet

    (4) I carefully match

    the cut areas of the

    rootstock andscion

    Grafting technique is shown

    below in the drawing

    Long matured

    shoots of

    Crataegus oxya-

    cantha Pauls

    Scarlet, which will

    be grafted on therootstock of

    Crataegus monog-

    yna. Note the buds

    at the side of the

    shoots

    The healing is a gradual process, the rate being directly

    related to the health and growth of the tree. You can

    only graft plants that are genetically of the same

    species. A pine grafted on to hawthorn is impossible.

    Grafting toolsA Grafting knife: with a good grip.You should have a

    very sharp knife because if the wound is untidy or

    jagged the graft will take longer to hold. Some material

    to bind the graft to the stock cloth, raffia or elastic.I use elasticised string because this is easy to work

    with. Another advantage is that it adjusts to the thick-

    ening of the trunk and wont bite into the bark.

    Wax for graftingI normally use wax which needs to be heated on a

    stove. The wax should start to melt, but not allowed

    to boil or become hotter than 80 degrees Celsius

    because it starts to burn. You can easily apply the wax

    on to the graft with a brush. Wax stops the graft from

    drying out and protects it from infections. If your graft

    is kept in a polytunnel or cold frame, you neednt apply

    the wax because the higher humidity can cause the

    graft to rot beneath the wax.

    Correct rootstockThe rootstock should be free of viruses and fungi. Try

    to obtain trees with trunks of the same diameter and

    which are true to type. The root system should be

    good and spreading. For this I use the hawthorn

    species Crataegus monogyna or laevigata.

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    The graft is held tightly to the rootstock while elasticised tape is

    wrapped around the point where both ends meet. The end should

    cross over your finger; then you slip the end under your finger-tip

    and pull your finger away. After which the tape will fit tightly

    around the graft.

    At work in the polytunnel, grafts aretreated with wax and planted in a

    crate with Torf. Later these will be

    planted in the open field.

    This is a graft with six buds, too many for such a small shoot and it

    is possible that it will dry out. Shorten it to three buds and you will

    have more success, and with a better chance of the trunk fattening

    (Above left) Here you have two examples of grafting methods: the

    top example shows that when the rootstock is thicker than the

    scion it is grafted on the side . The lower example shows the result

    of the method I use

    (Above right) wax is being applied to the wound

    Obtaining fresh scionsScions are obtained from matured 1-year-old shoots.

    With Prunus or hawthorn these shoots are easilyrecognised because they are long and grow straight

    up. I always ask at nurseries if I can remove such

    shoots and make sure that I only select those that are

    free of virus and pests and that they have no other

    damage. The cut shoots should have a between 3 to 5

    buds. Directly after taking the shoots they should be

    wrapped in a plastic bag and stored in the fridge, cool-

    ing them to between 0.5 and 3 degrees Celsius. The

    shoots for the scion will remain fresh for about 14

    days, after which they can no longer be used for

    grafting.

    When to graft?For successful grafting, it is necessary that the plants

    cells are active round the spot where you are going to

    graft. To promote cell activity you need a temperature

    of at least 13 degC, but it shouldnt be too hot either

    the maximum temperature to encourage cell activity

    is 32 degC. The best growing temperature is 20 degC.

    I start to graft hawthorn in early spring say around

    the end of February or the beginning of March. The

    advantage of this timing is that the plant is still

    dormant.

    AftercareAfter grafting you can place the plants in a cold frame

    or polytunnel in a growing bed of Torf (sifted pinebark). With plastic, protect them from severe frosts or

    the occasional sunny day, but remove it when it is not

    needed to let the plants air and prevent them from

    budding. Check regularly for fungi or pest attacks. In

    April when temperatures rise, you can plant the stock

    in open ground 20 centimetres apart, so that all buds

    receive enough sun to promote equal budding on each

    trunk.

    After one growing season all side branches should be

    pruned back to 5 cm to promote a dense branch struc-

    ture. The grafts can be lifted during the second year

    and the root ball pruned to promote a fine root struc-

    ture. Even the branches are reduced at this time. To

    obtain a trunk with a better taper, the top is reducedto a side branch from which the trunk will grow on. If

    you prefer, you can choose to grow the graft in a

    training pot, but from my experience I can tell you that

    nothing beats the results you get from the open field.

    The trunk will thicken less in a pot.

    Pests and diseasesAll hawthorn are vulnerable to mildew, gall, midge and

    scale insects. Start to spray with pesticides before the

    buds sprout, to prevent growth slowing down.

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    You can buy the wax in the spe-

    cialised garden sundries outlets

    where nurseries do their shopping

    Elasticised bindings to hold the

    scion and rootstock together

    This forest planting consists of

    hawthorn (Crataegus oxyacan-

    tha Pauls Scarlet) which I

    grafted entirely myself. The for-

    est is only a couple of years

    old, but the trees were trained

    in the field for more than five

    years. The grafts are hard to

    identify (detail left)

    61

    Not just a knife, this is a special grafting

    knife with a curved blade

    The wax is being melted on an electric

    hotplate; its important not to let it boil