Cloning a plant, also known as asexual reproduction, is the process of producing genetically identical cuttings that all descend from the same plant. This means these clones are rooted cuttings that have the exact same characteristics as the mother plant you took it from.
There are several advantages to cloning, making it popular among both commercial and home growers:
- Saves time and money with no need to buy and germinate new seeds.
- Produce a self-sufficient garden.
- Create replicas of your best performing and favourite plants.
- If you need to limit the amount of plants, you do not have to keep the “mother plant” after the clones enter the flowering stage. When you need more plants, you can use one of the cuttings as a “mother plant” so you can keep growing the cannabinoid profile of your preference.
Making cuttings is a fairly simple process and the theory is simple but there are some steps that you need to pay attention to and be careful about.
Clones will usually root in a few weeks but some of the cuttings will never root, so make sure you have a large number of cuttings. This way, in the end you will have some nice, healthy plants that will produce some big, fat buds.
The cloning process goes as follows:
1. Select and prepare a “mother plant”
Do not hurry this step. Make sure that you choose a plant that produces great yields and strong buds. Choose a plant that is a fast grower and of course, one of your favourite strains.
If you are new to this and do not have any experience to know which is the best choice, just go for a plant that looks healthy and is a good grower.
It is best to choose plants that were germinated from regular seeds. Plants produced from female seeds may also work, but since the process of making a plant produce only feminised seeds induces stress on the plant, if the plant is stressed again it might turn into an hermaphrodite. This will compromise your chances of having nice, healthy, bud forming plants.
The chosen plant needs to be at least two months old.
The stage of growth in which the “mother plant” should be creates a debate among growers: some defend that the plant should be in a vegetative state for 3 weeks. Others say that clones can be taken when the plant is about 3 weeks into flowering stage. There is no real consensus about this. Most cannabis experts defends that cloning flowering plants is completely against the rules of cultivation.
After choosing the “mother plant” you can prepare it by not fertilising it a week or two before you take the cuttings. This will make sure that there is no excess of nitrogen in the leaves and stems, so the energy of the cutting will be directed to rooting.
2. Taking the cuttings from the “mother plant”
When taking the cutting you will need to work in a clean environment and avoid a lot of agitation of the plant and the cuttings.
Choose the lower branches to cut out. These branches would receive less light and will be struggling to survive anyway. Also, the lower branches are ideal for cutting because they are not yet stiff and will root faster. Choose the ones that look the sturdiest and healthiest, with at least 20 cm and with two leaves or several nodes, if possible.
Make the cuts as close as possible to the main stem, with a cleaned razor, in a 45º degree angle to increase the rooting surface of the cutting.
After making the cuttings, place them immediately in water so that no air will enter the vascular system of the plants. If air bubbles form in the stem of the cutting, they will prevent water absorption and it will compromise the growing of the plant.
Remove all mature leaves from the cutting. If they are all mature, leave one pair of leaves.
3. Placing the cuttings in a rooting medium
There are three main schools of thought defending different rooting mediums: the rockwool method, the potting soil method and the water method.
At this point you will need a rooting powder or rooting gel to dip each cutting before placing them in the chosen rooting medium.
With the rockwool method you need to get rockwool cubes (a non soil equivalent will also work well. Ask about it in your local grow shop) and soak them in water for a couple of hours (test that the pH of the water is around 5,5) .
Rockwool has a lot of airflow and retains a lot of moisture, making for a excellent growing medium for your cutting.
Dip the cutting in the rooting gel/powder and place them in a rockwool cube. Keep the temperature between 21ºC and 25ºC degrees and high humidity (around 90% would be perfect).
In the potting soil method the cuttings are transferred to saturated soil after the stalk is dipped in rooting gel/powder.
Make sure to choose a soil that does not have too many nutrients.
In the water method, as the name says, the cutting will be placed in water for its roots to grow. Choose a container with a bottle neck to help the plant hold up straight.
Simply place your cuttings in a water container and keep them there until roots start to develop. The roots will start to develop more or less at the same time as new leaves.
With this method some defend that there is no need for rooting mediums, while others believe that the water used should be treated with plant food. Both ways work.
Mix the water every couple of days to prevent algae formation. If this happens, just change the water.
Each of these methods have pro and cons. Just see which one fits you best. Maybe even experiment the three of them to see which you are more successful with in producing healthy clones.
4. Transplanting the clones
You will know its time to transplant the clones when there is new vegetative growth.
You should get large containers in which the clones will develop into a full mature plant.
During this step you also need to work in a clean environment and you should be very careful to avoid transplant shock that can compromise the growth.
Transplanting from the rockwool and soil is like transplanting any seedlings.
If you used the water method for rooting, put the water container with the cutting next to the pot to where you are transferring it to. Open a hole in the soil and then transplant the clone, while trying to keep the roots from being exposed to air. Fill the hole with the remaining soil and press down gently.
Clones that have already started to root will have a high chance of survival. A clone with roots is no different from the strong mature plant from which the cutting was taken.
Clones will not look amazing in the beginning but if they survive, you should now have plants that get into the flowering stage within two or three months.
Taking care of your clones
The clones should be kept in a warm room between 22ºC and 27ºC.
Since the clones have little or no roots, you can spray them with water several times (daytime is best), so the plants can absorb water through the leaves. If you like, you can add some nutrients to the water as well.
If you prefer, you can place your clones in a humidity dome, like the ones easily found in gardening centres. This will make sure that humidity levels stay high so the plants will not die. If using a dome, do not forget to ventilate it each day, to prevent mold growth.
In regards to lighting the clones once they have been transplanted, expert opinions also differ. Some growers will not use any lights in the first days, while others start immediately with bright light (that will be later changed to a dimmer grow light). Both options are valid.
If using lights, make sure that there are some hours of darkness each day. A ratio of 16 light hours to 8 dark hours works well.
The best chance for your clones to grow healthy and strong is to keep a constant and close care of them.
Notes for outdoor growers:
Cloning will be more successful if you live in a place with a long growing season.
Your cuttings will start to grow three months into the growing season, which is when your mother plant is mature. So even with an extra long growing season, the clones may not reach their full potential. The longer the growing season, the better chance they have.
On the other hand, history has shown that short clones can end up producing amazing yields.
Remember to take great care of your plants so your cloning experience can be a success!