Cloning cannabis is widely used for propagation for a number of reasons. While the name might make the process sound complicated, cloning is essentially just another name for taking a cutting from the plant and allowing it to grow roots. In this guide, we will cover cloning and show you an easy way to make your own clones.
What is Cloning?
Cloning simply means to make a copy of a living things genetic code into another living thing. Cloning animals is a very complicated process - remember the triumph that Dolly the Sheep was? With plants though, it can be very simple. You have probably cloned a plant before, or have seen others do it.
Cloning a plant is as simple as cutting a small branch off the plant and then putting it into water, dirt or some other wet medium to grow roots. This is a very common practice with household plants like geraniums.When the cutting grows roots, it becomes a genetic copy of the parent
When choosing starters for your cannabis crops, there are only really 2 options: start from seed or start from clone. While seeds have their own advantages, there are a number of reasons why you would choose to start with clones.
Cost: Cloning is much cheaper than growing from seeds because you can start with one plant and end up with hundreds of clones.
Time: Cloning can be faster than growing from seed if conditions are right for the clone.
Uniformity of size: Since they share genetics, if clones grown in similar conditions will grow in a similar structure. If all the plants in your tent are clones of the same plant, you will get more uniform growth which will allow you to optimize light and space.
Uniformity of effects: Due to shared genetics again, clone's flowers will produce similar effects. With seeds, THC and CBD may vary considerably across a strain, while clones are more likely to have very similar makeup.
Seeds Are Not Always an Option: There are some important strains in cannabis history that have only existed as clones, like the original God, Bubba Kush and Amnesia strains. While these examples were eventually recreated as breedable versions, they originally were only propagated through clones.
Overall, when growing multiple plants from seeds of the same strain, you are much more likely to see broad variations in size, quality and output than in clones. On the downside though, this means that they also have the same vulnerabilities. If the mother plant was prone to mold, so will the clones.
How Do I Make A Clone?
There are a lot of techniques for caring for clones, but at the basic level, it is always some variation of the following:
- Cut a branch with at least 3 nodes on it
- Put the branch into growing medium
- Keep the plant in humid conditions until it grows roots
- Once the clone reenters vegetative growth, grow it like any plant
We will show you a method that is very simple and leads to great results. Over time, you can refine it to work better for you.
Step 1 - Prepare your Mother Plant
There are a few considerations on picking the right mother plant. First off, make sure it's a plant you like, because you are about to make copies of it. You'll also want to make sure that it's big enough to take the clones from.
Topping an unruly plant is a great opportunity to take clones, since you are cutting them off the plant anyway. For this guide, we used an adult female plant that had grown lopsided and needed a hard cutback anyway.
You can take cuttings from adult plants in any stage of life, but it takes much longer to root cuttings that are taken out of flowering. The resulting plant also has crazy bushy structures, making the process of cloning be known as 'Monster Cropping'. For beginners, we recommend taking cuttings from adult plants in the vegetative state.
Step 2 - Prepare the Containers
Use a solo cup sized or smaller container for clones. We use clear plastic drinking cups with holes in the bottom. After planting the clone, we will put the clear cup inside a regular solo cup to block light, and then pull it out to check on root growth. You don't have to do this, but it is handy to know when it's time to transplant.
Fill the cups with growing medium and water it to be fairly saturated. We use a coco and perlite mix for clones, but you can also grow them in soil just fine. Get a glass of water ready to, you will want to put the clones in water immediately after cutting.
Step 3 - Take the Cuttings
For best results, take cuttings that are at least 4 inches (10 cm) long. Since first roots form in the cut area of the clone, cut at a 45 degree angle to maximize this root growth surface area. Make sure you use sterilized and sharp equipment to cut so that you don't pass disease to the mother or the clone. Put the cutting into water immediately after cutting, or air bubbles can get into the plant and prevent root growth.
Before planting them in their containers, cut lower leaves off while the cutting is still in the water. Minimize the amount of time that the plant spends in open air.
Rooting hormones can speed up root growth drastically in clones. They are available at most gardening stores and come in a powder form. If you want to use rooting hormones, pour the powder onto a clean surface and then roll the cut end in the powder before sticking it into the moist soil. Put the cutting about half way down into the container.
Step 4 - Keep them Warm & Humid
After being cut and stuck into a growing medium, the new clones will be in shock and take a number of days to start developing roots. After a week or so, it should start developing roots that can help sustain it, but in the meantime, it won't be able to draw moisture and nutrients from the soil. Instead, you will need to provide water and nutrients to the plant through the air. To accomplish this, we need to keep the clones in a high humidity environment so that water is available in the air. We will also use a foliar feeding spray to get them nutrients.
You can buy humidity domes for cloning cannabis, but we just use two plastic bins - one on the bottom and one placed upside down on the top to form a lid. Then we place the homemade dome on a plant heating pad and keep it between 80F-85F (26.6C-29.4C). Using the heating pad under the bins to generate heat will encourage the roots downward growth. Spray the plants frequently with a fine mist that they can absorb through the leaves. This will also increase the humidity in the dome, which will make more water available to them for consumption through the leaves.
After a few days of seeming stasis, with droopy leaves and stems, the clones should begin coming back to life. The leaves and stems should become more turgid, showing that they are consuming water through the leaves and maybe even developing small roots. The overall color should become more green, showing that photosynthesis is happening. Once you are sure that the roots have grown enough to help with the plant's intake needs, lower the humidity levels over time to encourage more root growth.
For lighting, start with fairly low levels of light (like a compact fluorescent) and then ramp up as the plants develop roots. Without roots, they can not keep up with the water and respiration that heavy photosynthesis requires.
Step 5: Transplant
If you use the clear cup method, it will be clear (pun intended) when it's time to transplant them: you will be able to see the roots encircle the cup and begin forming a root ball. It can take anywhere from 10 days after the cutting to a full month before you reach this state. Using a humidity dome and heating pad will make sure you stay on the lower edge of this timeline.
At this point, the plant itself should be growing new nodes and new leaves. You will see bright green in the new growth, while the older growth keeps the dark green colors. The plants below took about 14 days to reach this state from new cuttings.
Transplant them the same way you would any plant - we have a guide to help with that. Once transplanted, you can treat and care for them like any plant in the vegetative stage - which means that you can top them and train them like any plant. Its been my experience that clones have a bushier growth pattern than seed-grown plants, which can help with sea-of-green, SCRoG and other training methods.
Cloning Produces Results
There are lots of reasons to use clones, in fact, many commercial grow operations use cloning exclusively. Luckily, the process is fairly simple and easy to be successful at. The end result gives a uniformity of plants that allow you to optimize your indoor grow space and produce predictable and repeatable harvests. The four clones we took for this guide ended up filling the whole tent in a Screen-of-Green grow.