How to Clone Marijuana
What is Cloning?
Cloning is a way of propagating plants through asexual reproduction of the plant by cutting and rooting a healthy shoot. This creates clones. It is also known as ‘taking a cutting’.
A clone has only one parent and is an exact genetic copy of that parent. This can happen naturally to many types of plants in the wild through a variety of processes, for example, when a strawberry plant lays down runners the resulting baby strawberry plants are clones of the original. Because of this natural ability the cloning of plants is separate from the controversy and ethical debate that surrounds the cloning of animals.
Over many thousands of years humans have exploited this ability to select plants that have particular desirable properties like high yields or pleasant flavors. Marijuana farmers are no different.
The donor plant is often referred to as a ‘mother plant’. Your cloned marijuana is generally taken from a mother plant while in its vegetative stage. While they may be taken from your plant while flowering, the clone itself must revert to the ‘vegging’ stage and the hormonal shift required will slow down growth as the plant gets ‘confusing’ signals.
Notice how similar all the marijuana plants are? This makes it much easier to control growth and spacing.
Why clone cannabis?
There are several ways that cloning marijuana can be beneficial to the cultivator:
- It is possible to ensure the gender of your plants. They are genetically identical to the mother, i.e. female;
- You can save money on seeds;
- You can produce large quantities of new, individual plants;
- When you have a high yielding, good tasting, or particularly potent individual plant you can replicate it.
Although we recommend elsewhere on this site that you spend as much money as possible on good seeds from a reputable company, this is only to get you going. With a well designed grow room programme you can be self sufficient for cuttings, growing only the highest quality weed from cuttings that you have selected yourself. Although all new smoke will taste the same as the last (given the same nutes); as it is genetically identical.
How to take a marijuana cutting
The first step in cloning your plants is to take a cutting. Although it is possible to take a cutting from a flowering plant we would advise against it. Once your plants are flowering leave them to do their thing – that is, growing top quality weed for you.
- Choose a healthy plant with at least 6 nodes or 4 weeks old as the donor;
Take cuttings from young pre-flowering plants. Once you have selected the phenotype that you desire, and are assured of its sex, keep it growing under 18-20 hours light to prevent it from entering the flowering cycle. This will be your mother plant and with good care she will provide you with an almost limitless supply of cuttings.
Some growers like to take cuttings from all of their plants (before flowering) as a matter of routine, especially if growing a batch of plants from seed. These cuttings are clearly labelled to correspond with the parent plants. Then, when the parent plants are finished it is possible to select the best one and choose the relevant clone. Now your next batch of young plants will be exact copies of your favorite adult.
- To take a cutting you will need a clean, sharp razor blade, scalpel or sharp scissors. Sterilize the cutting edge with rubbing alcohol;
- Make a cut at a 45 degree angle, i.e. on the 45. Select a green branch quite low on the plant with 2 or 3 nodes, (not a fan leaf. Avoid woody branches. Using the razor cut the branch at a diagonal angle about ¼ inch (5-10mm) below a node.
Rooting your cutting
Your marijuana cutting requires four things in order to root:
- Low light to stimulate rooting. As the clone will not be adding leaf mass or performing significant photosynthesis, more is not better. The light basically triggers certain hormones;
- A support structure;
- Moisture around the roots;
- High humidity to keep the leaves from drying out.
The simplest way for a single clone is to put your cutting in several inches of water in a Dixie cup and cover with a plastic baggie to retain moisture. Change the water every 3 days. Marijuana clones will root in roughly 6 to 14 days. Just prior to the appearance of the roots, white bumps will be visible on the lower part of the stem submerged in water (if that is the method you are using). Some gardeners transplant when the roots are 1” long while others wait until they are 6” long. Personally we like to wait until they are at least 3” long. Longer roots take more time, but generally results in less shock when transplanted.
Rooting marijuana with a gel or powder
Although it is possible to root cuttings in water it is recommended that you use a rooting gel or powder. Remove the bottom leaves from the cutting and dip it in the rooting compound, then plant the cutting in your desired growing medium. Rockwool cubes work particularly well.
At this stage the cutting is very fragile. Do not force it into the growing medium. Make a hole with a pencil and gently place the cutting into the hole, closing the hole around it with your finger tips.
If you take the cutting from just above a node on the plant, then that branch will split into two as if you had pinched it out. This way your mother plant will produce an exponential number of cuttings and keep you happily supplied with babies for your nursery.
Once all your cuttings are ready and in their pots, give them a drink of water and a mist from a water sprayer. Ensure that no light can reach the roots. If you have several cuttings put them into a propagation tray with a plastic lid, this will help limit the effects of transpiration and ensure that the plant holds onto plenty of water. Remember at this stage the young clone has no roots so must absorb water through the leaves and cut stem.
The young plants will need light, but in this fragile state it is important not to burn them with hot lights. Start with a fluorescent light or full spectrum LED grow lights at about 10 inches (25cm) away and gradually move it closer as the plant develops. If you don’t have space for a separate nursery area place the young plants in the grow room, partially shaded by the leaves of the mother.
Advanced marijuana rooting methods
This only works if you have a long low branch and if you are growing in soil. Make a small shallow hole a few inches deep in the dirt half the length of the branch from the main stem. Bend the branch down low enough so you will be able to bury it in the center. Scrape the lower outer part of the stem to be buried. Apply rooting powder or rooting gel to the wound. Push an unfolded paper clip or small piece of stiff wire over the center of the branch into the soil to pin it down and cover. After two weeks or so, the branch should show fresh growth. At this point, you may cut it away from the female and transplant into its own container.
- Choose any sufficiently healthy branch from your plant with a growing tip and gently scrape the stem around three nodes from the tip and about 1-1.5” long. Put rooting powder or gel on the wound and wrap with a small piece of rockwool or sphagnum moss. (An alternate might be to wrap with a paper towel or clean cotton fabric.)
- Soak the wrapping with plain water and cover with plastic wrap to keep the stem from drying out.
- Tie or tape to the branch. Not too tight, just enough to keep it from slipping. Twist ties work great. After several weeks, the stem should have developed new roots at which time it can be cut from the marijuana mother plant and transplanted. If you are not sure if it has rooted, you can carefully unwrap and check before cutting.
Aeroponic cannabis cloner
These may be purchased online or from most any hydroponic shop or built yourself (DIY). Essentially it requires a waterproof tub or bucket, PVC plumbing, a water pump and neoprene collars or net pots to hold your cuttings, an air pump and possibly a timer. If you are doing more than four marijuana clones at a time, this may well be the way to go for you.
Other cloning gear includes, clonex cloning gel, ez-cleaner, botanicare clone machine, clone bucket, aeroponics cloner and the homebox cloner.
Caring for new cuttings
Over the next couple of weeks your new plants should develop their own root system. Remove the propagator lid and fan the plants every day to ensure adequate ventilation. It is worth making a few holes in the lid to help with this. It is also important not to overwater these young plants. Roots need oxygen to grow so make sure that they get proper drainage. Feed the plants on just water for the first few days and then begin giving them a very diluted nutrient mix. After about two weeks, when you can see the plants’ root systems becoming strong, the plants can be re-potted into larger containers and take their place in your growing system.
That’s how to clone marijuana!
Check out our marijuana seed strain reviews guide to find out more about different strains of weed and where to purchase them.