I think you will be most surprised if you had to know just how many internationally famous bonsai trees were started from humble cuttings. It is a very simply method which anyone can use to begin a new tree, and of course is a technique which is not unique to bonsai growers alone but used frequently by enthusiastic gardeners, professional nurseryman and even fruit farmers.
Image caption. Some styles such as this Japanese Zelkova in broom style are grown exclusively from cuttings or are layered, to achieve the required nebari.
So what is a cutting?
Quite simply it is a piece of the branch or stem from an existing plant which is cut, separated from this "mother plant," treated and stuck into a growing medium.
Whats so good about cuttings?
Well there are several reasons in fact why bonsai growers in particular should be keen on cuttings and this is because:
The roots which emerge from a good cutting do so roughly at the same level and radiate evenly outwards from the stem. This gives you a massive advantage and head start with creating great surface roots or otherwise called "nebari."
The cutting will have identical characteristics to the plant from which it was cut. So if you have a neighbor who has a Chinese maple tree with really nicely shaped leaves then a cutting from that tree will produce the identical characteristic.
Another benefit to this form of genetic duplication is that some flowering species such as the wisteria can take many years to flower if grown from seed. However if you take a cutting from a flowering specimen it will begin flowering almost immediately.
Seeds are a very popular source of bonsai material but attaining a tree of any significant size from a seedling takes many years. You can save a lot of this time if you can find a mother plant of the same species from which you can take a cutting.
For many people starting out in bonsai the initial investment in tools, pots, and trees can be significant. However cuttings, aside from the rooting hormone and medium will cost you nothing, so its a very budget friendly way of increasing the size of your stock.
Image caption. Some species can be reproduced by using cuttings of their roots. I started this variegated leafed variety of elm above from root cuttings taken when I repotted the parent plant.
What types of cuttings are there and when is the best time to take them?
Softwood or Greenwood cuttings: These cuttings are taken in late spring generally and are of the current seasons growth that is still green. These cuttings tend to be the most fragile.
Medium or Semi hard cuttings: These are cuttings usually taken in Autumn and are of plant material from this year's growth but which has become woody near the end. The growing tip is still green however.
Hardwood cuttings: Hardwood cuttings are taken in late Autumn or winter after the leaves have fallen and vegetative growth has hardened to a woody appearance.
How do I take cuttings?
With the theory behind us its down to the fun part now.
Find a plant which you like for whatever reason, and considering the time of year determine the required type of cutting and the necessary rooting hormone(Go out and get the hormone you require before you take the cuttings and don't use that opened bottle which has been on the shelf for the last 5 years as the hormones will have become less effective over time).
If you are taking hardwood cuttings in Autumn, as depicted in the example above, then remove the leaves using a sharp pair of scissors.
Cut the branch or twig close to a set of buds, and in sections of around 10 - 15cm in length. Its very important that you use a sharp pair of scissorsto do this so that you do not damage the cambium tissue in the process, which will reduce success. I generally use a pair of scissors to cut the branch but then I recut the end with a grafting knife.
Immerse the cuttings in water to keep them moist till you have finished with them. If you are storing the cuttings to bury them later then you can wrap them in some moist paper-towel and then wrap in plastic and keep in the fridge or somewhere. (I have never done this myself as I always only take cuttings when I am able to plant them immediately)
Dip the cutting into the rooting hormone. (There are essentially 2 types; the liquid which you dilute a certain number of drops with water and the powder, which you dip the cuttings into. I've used both and I think I prefer the powder as I also use the powder when I am doing layering. However I understand many professionals prefer the liquid.)
Tap the cutting gently to remove any excess of hormone powder.
Push a stick, chopstick or rod into your already moist rooting medium and gently insert the cutting into the hole. Firm the medium around it. Don't shove the cutting into the medium as you may remove a vast amount of the hormone powder in the process.
Repeat steps 5 through 7 until you have filled your container with cuttings. Space them apart so they do not make contact and have perhaps 2 or 3cm gap between them, although this might increase for larger cuttings.
You will note in step 7 that I mentioned the growing medium should be moist before you begin inserting the cuttings. This is as you don't want to water the cuttings immediately after inserting them as the water will wash away the hormone. Instead, after completing your cuttings place the container into partial shade, protected from any wind and allow the growing medium to dry out somewhat (must remain moist though) and then wet again thoroughly till water runs from the drainage holes.
When the cuttings have started to root you will see new leaves emerging. Always keep the rooting medium slightly moist or your cuttings will die as the tender new roots cannot tolerate dryness for any given length of time. You can feed lightly with an organic fertilizer also.
Notes on rooting mediums
You can root cuttings in just about anything, provided there is plenty of drainage. So something like LECA, Groperl, Coco peat, River Sand (2-4mm) or Vermiculite or combinations of these is good; and Bark, Potting Soil, Loam etc are not so good as they retain too much water.
Notes on rooting containers
You can pretty much use anything from a yogurt container to a ceramic bonsai pot. You really just need something which will be deep enough to hold the cuttings you have taken and will provide good drainage. Purpose made plastic trays are ideal as they have plenty of drainage and have good structure to movement does not disturb the cuttings.
Well that's it, go out now and have fun with cuttings! Before you know it you are going to be giving little rooted cuttings away to friends. And don't forget when you are pruning your bonsai, have a little container of water nearby so you can immerse what you cut and treat them as cuttings later.