Cannabis Clones: The What, How, And Why

In biology, a clone generally means an organism produced asexually, genetically identical to the original organism from which it came. For plants including cannabis clones, it’s much simpler and usually referred to as cuttings (or cuts) – the act of cutting a branch from a pre-flowering plant to make an entirely new, genetically identical plant.

What are cannabis clones

Cannabis clones are made by clonal propagation, also known as vegetative propagation or asexual reproduction, a well-established process of generating new plants. Instead of reproducing sexually through pollination to produce seeds, clonal propagation involves removing the vegetative plant parts from the parent, to form the starting material for a new plant. This makes original and new plants genetically the same, and therefore they have the same phenotype. Although environmental factors will influence a plant’s phenotype, cannabis clones are generally an assured way to preserve and transfer the most revered and elite traits from the parent, into the grow room.

Cloning has been used for generations to share and preserve significant phenotypes for many species. Cannabis Seeds have advantages over cannabis clones, but it is also true that cannabis clones have some advantages over seeds depending on application, expected outputs and growing environment. Whether a grower would use cannabis clones over seeds or a combination of both, is entirely dependent on the grower and their purpose.

The benefit of using cannabis clones

Cost, speed and perseveration of elite breeders' cuts are often the reasons cited for using cannabis clones. Cloned plants help growers control the varieties' outputs, meaning results are more predictable than when growing from seed. Since cannabis clones are genetically identical, growers have an accurate description of what their crop will be like before it is finished. Therefore, this ensures something of a guarantee that the elite traits of the cannabis parent, are present in the cannabis clone. This holds many advantages, outwith speed and cost-effectiveness. For example, if pest or disease-resistant cannabis clones are available, then your crop will be pest or disease-resistant too. Most elite cannabis clones are chosen for their durability and vigour, meaning these traits are in the bag, so to speak. Clean cuts which are pathogen -free do not have seed-prone diseases such as Hop Latent Viroid (HLVd). HLVd-free cannabis clones which do not carry the elusive symptoms of the disease are sought after in all markets around the world.

Cannabis clones can be produced rapidly, cheaply and in high volumes if an established mother plant system is used or if purchased from reliable sources. In commercial cannabis production it is often the case that a mother room will contain enough plants to generate hundreds or thousands of cannabis clones weekly, depending on demand. The health, recovery and vigour of the mother plant is crucial to success and therefore must be considered the key component to a successful system.

Some cannabis varieties with unique genomic structure such as triploids, are available as triploid clones from elite breeders. The breeders cut, are special but the add in the triploid element and these varieties as even more special. They contain the next generation of breeding advancements, producing elite cultivars in triploid clone form.

Cannabis clones Vs cannabis seeds

Cannabis clones are generally quicker to grow than seeds and will typically provide a faster turnaround. In addition to the faster turnaround, having the ability to short cut the early stage of life means, in some set ups, more cycles can be done in a year compared to seeds. This can mean more profit for commercial growers and more top end flower for home growers.

Growing from cannabis clones helps preserve the genetics to the truest and highest degree possible – the breeders cuts. Whether generated in a tissue culture lab or cloned in a basement, the ability to reproduce a known outcome is why cannabis clones are chosen over seeds. The breeders' cuts tend to be some of the most elite cultivars available. Breeders' cuts are almost always pathogen-free from reliable sources, and even elusive diseases such as Hops Latent Viroid (HLVd) are rarely present in these elite cultivars.

Seeds have sibling differences, and even very uniform seeds lots can contain the odd genetic anomaly, i.e., a strange or different phenotype to the rest. Cloned cannabis plants have less variance, unless there is disease present or an unstable environment causing big microclimate variation.

Another advantage of cannabis clones is that even flowering plants can be reverted to the vegetative stage, where cuttings can then be taken. This means that you can flower your plant, decide if it’s a winner, and then revert it to make more clones of your new favourite cannabis plant – not for every occasion but it is possible and becoming a more common practise.

Mother plant selection

Selecting the right mother plant for cloning cannabis involves many considerations. To identify high-performing plants or unique chemovars, growers typically grow out high numbers of seeds to assess the many factors that make a good cannabis clone/mother. Factors like seed lot stability, growing environment, uniqueness desired and number of targeted traits influence the seed quantity required.

At one end of the scale, with unlimited time and resources, growers may use up to 100 seeds to find a few unique phenotypes. However, these phenotypes may not possess all the desired traits in a single plant. Some breeders and nurseries even go beyond 1000 seeds to match, replace, or improve their existing cultivar, particularly in greenhouse settings. They aim for optimal cannabinoid ratios, high concentrations of cannabinoids, maximum yield, and minimal hands-on management. In these cases, rare phenotypes may represent only 0.1% to 0.5% of feminized seed lots, necessitating the planting of 1000+ seeds.

Alternatively, some phenohunters find success with seed packs of 10-20 seeds. This approach is more common in smaller-scale indoor grows, where plant training and closed-loop setups reduce pathogen risks. The likelihood of finding usable phenotypes with fewer targeted traits can be around 10%. Genetic uniformity and seed quality can vary, and breeding for high THC indoors is relatively simpler compared to outdoor or greenhouse cultivation, which may require additional traits alongside the high THC.

How to make cannabis clones?

There are nuances to making cannabis clones/taking cannabis cuttings, however the general process is pretty straightforward. This is a quick list of one of the more common methods including the essential and useful materials to get the process going, assuming a healthy cannabis plant with the desired phenotype has been chosen to be the mother plant.

Cannabis clones can come in a few different forms. The most common two types are rooted and unrooted cuts. Unrooted cuts are exactly as they sound and are available to the grower sooner than rooted cuts. Growers find advantages with both rooted and unrooted cuts. Unrooted cuts (URC) are cuttings without established roots, requiring further propagation to develop a root system. These are often available readily and are easy to transport. Rooted cannabis clones, on the other hand, have successfully undergone the rooting process and possess a fully functional root system, making them more self-sufficient and ready for transplanting and further growth.

Materials & Tools For Cannabis Clones

Plant tray: Usually comes in black or white plastic. Use trays without holes.

Tray inserts: An insert that sits in the plant tray with square holes for the Rockwool to sit in, holds 50 cubes.

Humidity dome: Clear plastic Dome that fits securely over the plant tray and inserts. Has vents at the top for air circulation. Maintains humidity.

Grodan 1.5” Rockwool cubes – They come in slabs, wrapped in paper or bags. Moisten them with filtered water or a weak pH nutrient solution. Although the instructions say to soak them, you must shake out most of the excess, or you’ll run into trouble with clone loss from the media being too wet. Roots need air just as much as they need water; some say more so.

Seedling Heat mat – Cannabis clones will root well with a temperature between 75 degrees F, and 82 degrees F. the seedling mat will help maintain that temperature to the constant sweet zone. Set the temperature and the buffer zone so it will turn on and off when needed.

Gardening scalpel, sharp and clean – a tool to prepare the cuttings for rooting.

Gardening scissors, sharp and clean – a tool for cutting clones and general pruning.

Rooting solution – Powdered or gel. Clonex gel is regarded highly. Comparable results obtained with Cyco Cyclone gel.Use clonex solution – a great micronutrient-rich solution with just enough NPK to get things started. Apply to the rooting cubes and in the 10”x20” tray after rooting.

10 mL pipette – To aid in applying the rooting gel. The gel is expensive, and overuse is a common mistake leading to clone failure and unnecessary costs. LESS IS MORE here. Apply a thin line and work the gel around the cutting with the pipette.

300-400 mL of water- for the clone tray under the T50 insert.

Cloning cannabis step by step

Step 1: Prepare The Clone

Prepare a cup or measuring cup with filtered water and the appropriate amount of Clonex Solution. Make sure it is large enough to hold all of the cuttings you want to take. Using clean and sharp scissors/blade, take cuttings from your donor plant. Make sure you are cutting from the bottom and as close to the stem as possible. They should have three to four nodes on them. Cut the remaining lower nodes off if needed. Strip off all large fan leaves not associated with your nodes as well. Clip all of the remaining leaves at the tips. Cutting leaf tips reduces transpiration. Make clean, sharp cuts for the health of your plants. Place the URCs (unrooted cuttings) in your cup with the prepared Clonex Solution stem down. Continue taking cuts like this until you are finished and ready to move on to step two.

Step 2: Shaping The Clone

Take a URC from your cup and measure the cannabis clone against a measuring stick/the blade of your scissors will do. This keeps the cannabis clones' uniform in height for a more even canopy. Cut the excess off at a 45-degree angle. This will increase the surface area of the exposed tissue. Increasing the area from which roots can develop (although roots can form from differentiated tissue, it is better to expose the undifferentiated cells (stem cells) for root development).

Step 3: Prepare For Rooting

Hold the cannabis clone in your hand bottom up. In your opposite hand, use your scalpel to mark or scrap the surface near the cut end. This helps root development. Scrape just the outside layers of tissue. Cutting the stem at a 45-degree angle allows the rooting hormone to contact more surface area of the plant’s cells, thus increasing rooting chances.

Step 4: Applying Rooting Agent

Pour a small amount of Clonex into a small shot glass. Replace the cap. Never stick anything into a bottle like Clonex that makes contact with plants. Doing so will contaminate the entire bottle. Use the pipette to suck up some Clonex. Using the pipette, apply a thin line to the area you just prepared with the scalpel. Use the pipette to spread the Clonex gel all over the prepared area. This ensures you do not over-apply or waste Clonex. Using too much can kill the cutting before it can root, wasting resources. Less is more.

Step 5: Planting The Unrooted Cannabis Clone

Take your clone and place it in the prepared hole in the rooting cube. Push it until the prepared area you want to root is entirely enclosed in the cube. Do not push the bottom out of the cube. Place the cube in your tray, insert and repeat the process until complete. Cover all of your cuttings with the humidity dome and place the entire tray on the seedling mat. Set this under a cool blue 25–50-watt T-5 bulb. A stronger light is not preferred. The cool blue spectrum also aids in rooting. Plug in the seedling mat and set the temperature to 77 degrees with a +/- 2.5-degree variance. Put 300 to 400 mL of water in the bottom of the plant tray. Ensure that the bottom of the inserts holding your clones does not touch the water. The seed mat will heat the water in the tray and form a good warm, humid environment, preventing the need for spraying clones for humidity control. Leave it alone for three days. On the fourth day, open the dome to exchange the air by just pushing the dome's edge onto the tray, so it sits unevenly. Open the dome’s air vents to make a flow of air go into the dome. Keep the water in the tray from evaporating completely. Continue this for approximately 14 days or until all cubes have roots growing down into the water in the tray under the inserts. Your clones are now ready for transplant.

The cons of cannabis clones

The downside to using cannabis clones is also the reason why there are so many advantages. Generally, if there is a problem with one, there is likely a problem with all or at least many. If a cannabis clone has been selected which isn't up to the task, I.e., not suitable for certain outdoor environments as it has only been selected for high THC production, then it might be more prone to the elements when planted outside.

Overview of cannabis clones

Cannabis clones offer a much more controlled outcome and offer the breeders cut of elite cultivars. Cloning is an easy skill to develop, although there are key steps which must be taken to maintain high vigour throughout the growing cycle. It can be very cost-effective and quicker than seeds, resulting in more cycles and more production. As always, maintaining good conditions and optimising the environment remains crucial to successful growing of any kind.