Advice - Special techniques
This technique involves grafting branches onto a trunk in spots where
additional branches are needed. The procedure is done in the spring when
the rootstock is actively growing, whereas the scion should still be
dormant (it is advisable to put the rootstock in a greenhouse and keep
the scion in a cold environment).
The operation consists of drilling a hole the size of the scion through the trunk at the desired location. A wood bit at low speed should be used to avoid burning the cambium.
The hole should be drilled at a downward angle from 45 to 60°. The scion will tend to grow vertically and starting out pointing downward makes it possible to better position the branch.
There are two options:
- use a young, healthy and vigorous plant grown in a pot (a one- or two-year-old seedling)
- use a branch that was allowed to grow lengthwise (without pruning) during the previous season, without detaching it from the trunk until the graft has taken.
When placing the scion (without any side branches) in the hole, it is best to remove the bark from the part of the scion that will be in contact with the rootstock. The parts must fit snugly to ensure that the cambiums are in contact. To ensure even better contact, apply grafting wax as a sealant and stake the branch.
You will start to see the joint heal as early as June.
Separation is done in September.
As many holes as necessary can be drilled in a single operation.
The goal of root grafts is to improve the nebari.
It is done at the same time as repotting, in March or April, after the root hairs have been thoroughly cleaned to remove all of the old substrate.
Roots from the same plant can be used, provided that their diameter is at least 3 to 5 mm.
Use an awl to cut a notch the same size as the grafted root at the desired spot on the nebari, and position the scion to ensure that the parts in contact fit perfectly. Fasten the scion to the tree (one or more staples should do the job).
It is also possible to graft roots by drill-grafting, in the same way as drill-grafted branches.
The same operation can be conducted using a young plant whose roots are approach grafted at the nebari level, and, higher up, at the collar level to avoid an unsightly callus.
The technique is the same as that for approach grafting a branch. The plant comprising the scion is separated after a few months of growth, as soon as proper callusing has occurred.
All necessary precautions should be taken to prevent substrate from entering the graft (use of grafting wax with hormones).
The tree is then grown normally (watering, fertilization, etc.).
Within a few years, it is possible to grow trees with multiple
trunks, using saplings whose roots have been cleaned, and putting the
required number of trunks together (2,3,5 etc.). The trunks are fixed
together very firmly at the collar, using a sturdy, durable fastener.
The bark can be removed from the areas that are in contact to ensure
that they fuse correctly, but if you use young saplings and fasten them
firmly, the fusion process takes place by itself.
Preferably, these trees are then planted directly in the ground, although they can be put into sufficiently large containers.
A callus will develop at the collar. The fastener is left in place permanently. The nebari will be developed through successive repottings.
The goal of this operation is to encourage growth in dormant buds and produce smaller leaves.
In general, it is done in June through very early July on a healthy tree that has been correctly watered and fertilized, and gets plenty of light.
On some trees whose leaves are rather big, such as Acer buergerianum, you can just remove the few unwanted big leaves.
The leaf should be cut off with a small pair of scissors, leaving the petiole intact, because if you pull the leaf off along with its petiole, the dormant bud at its base will be injured and it will grow poorly or not at all.
This type of pruning weakens the tree considerably and it must not be done on a stunted or sickly tree, nor in the same year that the tree will be repotted.
Some varieties are very popular among amateurs, and many have Japanese names.
Many varieties are grown, but not all of them can be grown as bonsais.
- Deshojo, bright red leaves.
- Nomura , bloodgood, carmine red leaves.
- Katsura, akane and orange dream, with orange-coloured leaves in the spring.
- Arakawa, commonly called the cork bark maple.
- Ukon, soft green leaves in the spring.
- Seigen, beni chidori, prawn pink leaves in the spring, green in summer and orange red in the autumn.
- Okushimo, small leaves that are slightly wrinkled at the edges.
- Kiyo hime, kashima, and the murasaki kiyo hime variety with their red-edged leaves that work well in the hokidachi style.
- Higasayama, with its golden yellow springtime buds shaped like a parrot’s beak, followed by variegated green and white leaves.
- Kara ori nishiki,, karasu gawa and and Asahi Zuru coated in three colours: cream, pink and green.
- Shishigashira, with wrinkled, soft green leaves in the spring, dark green throughout the summer, and then orange red in the autumn. (Splendid!)
- Tsuma gaki with red-edged leaves.
- L’acer shirasawanum aureum with leaves that are bigger, but which take on a lovely lemon-yellow colour in the spring and turn fiery reddish orange in the autumn.
- The rarest and most original of the variegated Acer palmatums: fujuinami nishiki,, taimin nishiki,, and hana matoi.
- Varieties with decorative bark: Acer p. sango kaki the coral maple with pinkish-orange wood in winter.
- acer p. arakawa, the cork bark maple.
- acer p. ukon, with soft green leaves and bright green wood.
- Acer p. bi hoo one of the most recent arrivals with wood that stays a golden yellow all winter long. (splendid)
- The dissectums dissectum such as D. red dragon, and and D. seiryu with their lighter foliage that can be used to make plants with an airy feel.
- kamagata with its tiny leaves.
- hime shojo small, crimson leaves, short internode.
- Koto hime, goshiki koto hime, kurenai.
- For Acer buergerianum : joroku akame with crimson shoots.
- Goshiki kaede variegated white and pink.
- Nioi kaede or scented wood maple.
- And the brand new toyo tricolour with its orange, cream and brown leaves.
The species grown for parks and gardens are maples with large leaves such as platinoid Acers, Acer Saccharinum, or Acer Negundo. These are not suitable for growing as bonsais.