Propagation: Cloning Plants Step-by-Step

Thanks to cuttings, you can easily create genetic copies of your favourite plants. This method offers growers the opportunity to achieve consistent results, optimise growing conditions, and preserve exceptional plants. In this article, we will guide you through the cloning process from A to Z – from preparing the equipment to rooting the cuttings and transplanting them.

It will probably come as no surprise that sowing and germinating seeds are an inseparable part of gardening. However, this is not the only way plants reproduce. In addition to generative propagation (by seeds), plants can also reproduce vegetatively (from part of the plant). This is because plant cells have the ability of totipotency, which means that any of them can develop into an entirely new plant. In today's article, we will focus on a specific case of vegetative propagation, namely cuttings. For completeness, however, let us add that gardeners and growers also propagate plants vegetatively by dividing clumps, layering blackberries or grapevines, separating strawberries, grafting, and propagation by means of tubers.

Plant cuttings

As we hinted in the introduction, vegetative propagation of plants differs from sowing seeds. In the case of cuttings, we take a suitable part from the donor (mother) plant, usually the tip of a healthy branch with several healthy leaves and internodes. We then move the clones into a suitable growing medium, which is usually cubes made of mineral wool or a suitable growing substrate. For freshly cut cuttings to root successfully, they need suitable conditions, above all high air humidity, warmth, and plenty of light.

So how do cloned plants differ from those grown from seed? The main difference is that the newly formed offspring is a genetic copy of the donor plant. Clones therefore always have the same sex as the mother plant. One advantage is that, when growing dioecious species, growers do not have to worry about selecting males from females. Another benefit of cuttings is the genetic uniformity of clones. Because the plants come from one mother, they will show identical growth characteristics. Large-scale growers in particular can use cloning to optimise the growing process and achieve consistently reliable results over the long term. Last but not least, cuttings give growers the opportunity to preserve exceptional phenotypes in the form of clones over the long term.

It should be added that cloning also has some disadvantages. The main problem is the risk of transferring genetic disorders, pathogens, and diseases. If the mother plant is infected with one of the plant viruses (e.g. HLVd) or suffers from a genetic mutation, the offspring will be affected in the same way. The same applies to mould and many insect pests, but in these cases it is possible under certain circumstances to treat the clones with pesticides or fungicides. Unlike plants grown from seed, cuttings do not have a main root that grows deep into the ground. Cloned plants are therefore somewhat less suitable for outdoor growing, especially in places where they may face strong gusts of wind and prolonged drought.

Advantages of cuttings

• same sex and genetic uniformity
• uniformity of the crop
• preservation of exceptional plants

 Disadvantages of cuttings

• transfer of genetic mutations and viruses
• spread of pathogens and pests
• less suitable for outdoor growing

How to take cuttings step by step

Before you start taking cuttings, first make sure that you have all the necessary equipment. You will need a growing medium, preferably cubes made of mineral wool or a suitable propagation substrate. Cuttings need constant air humidity of around 75-85%, which is easiest to achieve in a small plastic greenhouse (propagator). Clones root fastest at temperatures in the range of 24-27 °C. Lower temperatures slow the process and increase the risk of mould. In the first few days, medium-intensity light (100-200 µmol) with a blue-white spectrum is suitable. After the first roots appear, you can increase the light intensity to double, which will speed up the development of the root system. At this point, it is also suitable to start using root stimulant. You can find grow lighting for growing cuttings and seedlings HERE.

Other necessary equipment

• scalpel
• disposable gloves
• disinfectant (alcohol, Purolyt, hydrogen peroxide solution)
• rooting gel
• thermometer with humidity meter
• container for placing fresh clones
• paper towels

Detailed guide to cloning

To give yourself the best chance of success when taking cuttings, take clones from recently grown branches from plants at the peak of vegetative growth. Before taking cuttings, you can treat the donor plant with one of the special products (e.g. Clonex Mist) that support root formation and strengthen the cuttings' resilience. Always work with clean tools, wear rubber gloves, and do not smoke while working.

1. First remove excess leaves from the branches and leave only a few young leaves at the top. Trim their tips so that 2.5 to 5 cm of the blade remains. The lower part of the future stem should remain bare.
2. Cut branches 10-15 centimetres long and immediately place them cut-end first into a prepared container of water.
3. Finally, cut the ends of the stems to the same length at a 45° angle. Immediately dip the clones prepared in this way into rooting gel and insert them into the growing medium.
4. Place the cuttings under the greenhouse lid or into a propagator and put them under a light source.
5. Depending on the plant species and conditions, it will take approximately 7-14 days for the clones to root and be ready for transplanting.
6. Throughout the process, check that the growing medium is moist. It should not, however, be waterlogged.
7. Towards the end of the process, gradually open the vents on the greenhouse to reduce air humidity and prepare the plants for transplanting.

Aeroponic propagators

Aeroponic propagators are based on a simple principle, in which the ends of the stems are exposed to a mist of oxygenated water. Thanks to the high oxygenation, clones root up to twice as fast as in another growing medium. Another advantage of aeroponic cuttings is that the clones can also tolerate lower air humidity in the range of 50-60%. This makes the subsequent acclimatisation of new seedlings easier.

Finally, for completeness, let us add that in recent years a new modern method of cloning using tissue cultures has also been gaining popularity. We will devote this modern plant propagation technique to one of our future articles, but if you know how to do it and want to try tissue cultures in your grow room, you will find cloning systems for tissue culture on our website.