Propagation – Expressions of Grace Bonsai

Cuttings and general bonsai upkeep

Xavier Martinez — Fri, 06 Aug 2021 13:25:56 +0000

If you are anything like me then you will really struggle to throw anything away. Every year, since I started in bonsai, I have spent as much time taking cuttings as I have in developing the trees. This was not a deliberate choice on my part – just a natural desire to use all of that discarded material. When I first began, I had no idea that there were techniques used for successful propagation. I just took an offcut and planted it into some garden soil. Any size and any time of the year that I was pruning…

Surprisingly, I had a reasonable amount of success during the early years so it never occurred to me that I was just lucky. I still have an eight-year-old Corkbark Elm that started off as a broken branch discarded into a compost pile.

I later learnt that Chinese Elm are particularly easy to propagate from cuttings – which did explain the success.

I take my cuttings twice a year. First, is sometime in late May / early June when the spring flush of growth has extended and hardened off. This also coincides with my pruning cycles and the increased temperatures / daylight hours. Ideally, we would want nightime temperatures to be above 15 °C to aid root development.

The second occasion occurs late July when I carry out my general pruning to maintain bonsai shape. I have most success placing the cuttings into damp perlite or vermiculite. They are then kept in a propagator or covered with an upended plastic bottle. I keep them misted but do not water. They are normally kept in a shaded part of the garden to reduce transpiration.

The best results come with: Fuji Cherry, Trident Maple, Chinese Elm and Boxwood. With indoor varieties I find that Ficus and Jade root very easily and all I need to be careful of is not to overwater them as they succumb to root rot quickly.

Cuttings taken June 12

4-6 weeks under cover

3 years later...

With Fuji Cherry I take a cutting from the point where the stem has changed colour and hardened enough to be self supporting. I remove the growing tip and around 3/4 of the leaves. I use a general purpose rooting hormone and then place the cutting into the soil medium.

I have used a range of potting mediums with success. The real issue is to ensure you establish a humidity bubble to stop the stem drying out. Don’t worry if the leaves fall off – shoots may still appear 4 -6 weeks later.

Cutting taken on 18 Jun

Year 1 Dawn Redwood Cutting

Year 2 Dawn Redwood Cutting

Year 3 Dawn redwood Cutting (Progression)

Dawn Redwood was a surprise success for me and though I only take 3 or 4 a year it is great seeing them develop. I tend to concentrate on last years unwanted growth as it gives me a thick stem. I use either perlite or sphagnum moss and then cover them to preserve humidity.

It is worth remembering that after a couple of years you should consider loosely wiring the main trunk to produce the movement you desire. Once the trunk thickens too much you have no hope of bending them!

4-6 weeks under cover

Year 1

Year 2

Year 3

Trident Maple are treated exactly the same and you can take up to a pencil thickness cutting. With the thicker cuttings I use sphagnum moss as the potting medium as I find this helps the hardened wood stay hydrated whilst the roots form. I normally leave two or three leaves on the shoots and remove the growing tip. I always cut at the base of an internode section.

I will take up to two dozen cuttings for each washing up bowl I use – success is up to 80% for me normally. In Year 1 I will thin out any obvious weaklings and then split them in year 2 to individual pots.

Larch Cutting about 6" long

Year 2

Azalea Heel Cutting

About 9 taken for this pot

A variety of this years cuttings

Japanese Larch are the hardest cuttings from my experience. I have tried a variety of times and methods and can boast the grand total of 3 successes in as many years! But at least that is three more than I had before – at no cost

Satsuki Azalea are best taken as heel cuttings. This is when you gently peel the shoot away from the trunk or branch. My success with these is also mixed and I have found the cuttings that have taken are extremely slow to develop. But again, they are free…

Mother Tree

Straight branch removed

Ground layer propagation

Three years of Chinese Elm cuttings

Like the Trident Maple, you can take very thick cuttings off of a Chinese Elm. They often propagate successfully without need of humidity covers and this time of the year I am planting all of my prunings into washing up bowls.

This spring I removed a large straight branch from one of my bigger Elms. I removed all of the bark on the lower side and wired it into some soil to attempt a variation of the ground layer technique. I definitely have new growth so time will tell…

I have found that so long as you apply the general principles to your propagation success will follow. It may be discouraging in the first year because they are still not bonsai but watching them send out new shoots is definitely rewarding. It doesn’t matter how many failures you have because the ones that do take will be your future bonsai masterpieces.

I definitely recommend you scouring You Tube for content on ‘how to take’ cuttings – there are loads of videos available. The only cautionary thing to remember is that we each live in different areas and it can be surprising just how varied results can be within our own ‘micro’ climates.

If you are ever confused at whether your cutting is viable it is worth taking a closer look at the rare but popular ‘dead tip’ variety. This is a sure give away that your propagation failed! Oh…and don’t be confused by the little green weed – that will never make a bonsai.

It is now the time to carry out 2nd pruning on your Japanese Larch but more on that in the next post.

Happy bonsaiing

Air Layering my Japanese Maple

Xavier Martinez — Sat, 18 May 2019 12:05:12 +0000

I have had this Japanese Maple for about 3 years and it has sat in a pot doing ‘not very much’ for most of that time. I always thought it would need an air-layer but because of a few failures with other maples I lost a little confidence. However, a recent tutorial with Bonsai Mirai reignited my desire to have another go. Those who are experienced with propagation and plant physiology will learn nothing new here – this is for the beginners!

An air layer can be taken from most trees in the UK once the first spring flush of growth has hardened off. This is usually around mid May and you should notice the leaves will have lost their delicate feel and will have a stronger color. At this time the leaf is in full ‘solar panel’ mode – it is converting energy back into the tree through photo synthesis. All of these sugars are sent back to the roots to rebuild the energy store needed for future seasonal growth.

The air layer process relies on the ability of the tree to produce new root growth from the exposed cambium at the point we have removed the bark from the trunk / branch. There is some ‘biology ‘ behind all of this so I will try to clarify exactly what is required to increase your chances of success. Have a look through the next few images to help you understand why and what you are ‘removing’ when we ring bark the tree for the air layer.

As you can see, there are a number of different layers made up within the trunk or branch of a tree. When we carry out an air layer we need to ensure we remove the following:

Bark
Phloem
Cambium

The aim is to remove a sufficient band of material that ensures the tree will not be able to bridge the gap between the upper and lower cuts. If we can do this then what should happen is the site of the upper cut will start to produce new root growth from the exposed cambium – in an attempt to repair the damage. Normally I will remove an amount equivalent to the thickness of the branch…and a little bit more.

Once that cut is made then there is no means for the growth above the site to transport energy/sugar back to the roots – it can however still obtain water via the sapwood. This means that if you do the air layer below the lowest branch you will have no means of keeping the roots alive. Hence a ‘limited’ period exists to get sufficient new roots to maintain the existing growth above your cut site. Clearly, if you are taking the air layer from a branch then their is no risk of compromising the health of the rest of the tree. It is not unusual to take numerous air-layers off the same tree. I have certainly done that with my cherry and maples.

There is a lot more detail on this subject; which includes the water transport system from the roots, but in essence, it is important to recognise why certain things are done and why there are time constraints. The aim is to take the air layer off in early autumn to give enough time for young roots to establish and harden before the winter.

I have selected a point above the ugly swelling and then cut away at an angle to try and establish a wider base for roots to propogate from. It is vital that this upper cut is done with a sharp knife and ‘cleanly’. You are trying to avoid any ripping or tearing to maximise the ability of this exposed cambium to produce new roots. You can dust the cut and above it with rooting hormone to assist some trees with this process.

I use pre soaked sphagnum moss as the growing medium that I pack around the cut site. You can use plastic as a wrap around the moss but I have had more success using an old plastic nursery pot with the centre cut out. I ensure that the top of the cut sits in the centre of the pot – this should be the best place for balance of water and oxygen. I use wire to secure the pot at top and bottom which allows an easy method to check for root growth later in the year. I pack the pot full of moss and then soil and water it. The rest is up to nature…

I will keep the soil moist and the tree in a shaded wind free spot until I am ready to separate the air layer. I am aiming for mid August so I will loosen off the wire and check progress sometime in late July.

If the layer has taken then I will cut the trunk beneath the container and try to ‘slip pot’ the seperated tree into a larger plant pot – without disturbing the root mass.

I have included an image of the maple (above left) showing the original lower half of the tree. Hopefully you can see the shape that the shorter bonsai will take once the air layer is removed. If things don’t go well then at least I will still have a better bonsai to work with next year…