Before we get started, let’s define our objective.
Cloning Cannabis: the act of taking a growing tip, cutting it, and creating an identical, self-sufficient replicate plant that has the exact same genetics as the mother. Genetics determine the traits a plant will express.
For those of you who are visual learners (like me!), I’ve created a short video tutorial that outlines everything discussed in this post. You can view it here.
There are two ways to clone, either by using an aeroponic cloning system, such as an EZ Cloner, or by taking the more labor intensive and nurturing approach of putting the cuts in a growing medium such as rockwool or peat moss pellets, and giving them periodic misting. Either method works great so long as the ideal temperature, humidity, and light are adjusted for the new cuttings.
How does the act of conserving genetics benefit farmers cultivating medical marijuana?
- Cloning helps farmers determine unique phenotypes (& sex!) without having to put the mother through flower, just put the clone to flower instead!
- If pheno-hunting for the purpose of finding a “permanent” mother (preferably from seed), cloning helps the farmer choose a desirable mother plant from a large batch and conserve her genetics and traits
- Cloning allows for an intimate relationship between plant and farmer. Most farmers utilize clones to run many cycles of the same genetics for years, eventually dialing-in every aspect of veg/bloom
However as with everything in life, cloning has its pros and cons. Personally, I believe there are more pros than cons when cloning your cannabis plants.
- Allows you to sex plants (for more info on this, check out our post on sexing plants here!)
- No potential male plants if sourced from a female mother
- The ability to replicate identical genetics, allowing you to maintain unique phenotypes and traits
- Faster than growing from seed
- Creates an environment for potentially spreading disease and pests if source was infested
Now, let’s move on to the act. Like every other aspect of cultivation, farmers add their own essence to the process cloning. Experience will allow you to tweak and optimize the protocol for what works best in your garden. This is merely the approach I take, conceived from various online resources and experienced growers who help spread knowledge.
What you will need:
- Mother plant—these are the genetics you wish to save.
- Scalpel/blade—This allows you to have control over the cut.
- Warm pH-ed water—I use warm water pH-ed to 5.6.
- Cloning solution—your choice. I prefer Clonex, but have and will continue to try new ones.
- Mycorrhizae—to establish a symbiotic relationship between the fungi rich growing media and the prospering roots.
- Medium—rockwool or peat moss pellets. I tend to use Plugs.
- Misting bottle—Fill with diluted cloning solution or a diluted cocktail from your nutrient shelves.
- pH up/down
- pH meter
- Rooting tray with dome cover
It’s important to note that Nitrogen inhibits cloning. Some sources state to flush the soon-to-be mother with pH-ed water (6.3-6.8) up to a week before taking cuttings. Personally, I do not do this.
Step 1: Choosing when and where to clone
Taking clones 2 weeks into flower is ideal, but if you are looking to sex or pheno-hunt then clones should be taken early in veg. As for where you should cut, you might remember our descriptions of cola sites from our last post on main-lining. Picture a pine tree (a perfect example of apical dominance). Like medical marijuana plants, pine trees demonstrate an obvious dominance in the apical/terminal tip–the pointed end where the star tree topper sits on a Christmas tree. At this tip (also referred to as the terminal bud) is where the highest levels of a particular auxin (a plant hormone termed indole-3-acetic-acid [IAA]) can be found. IAA is responsible for inducing cell elongation and cell- division, subsequently resulting in plant growth and development.
It is ideal to choose the “top” or “main” cola sites to clone, as they have the higher levels of the growth hormone IAA and the genetic instructions to be top nugs. But ultimately any growing tip will suffice.
Step 2: Cutting
Cut off the growing tip with the scalpel at a 45° angle. Make your cut good 4″-6″, big enough to have at least 2 sets of healthy leaves on it.
With the same scalpel shave off the stem’s outer bark exposing the cambium layer, a layer of actively dividing cells responsible for growth of stems and roots.
Step 3: Solutions
Immediately dip the clone tip into pH-ed warm water. Then dip in the cloning solution of your choice. Lastly, dip your clone tip into your chosen mycorrhizae.Place clone in your root-holding medium of choice and cover with dome. Repeat the process until you have the number of desired clones.
Step 4: Storage
Cover your tray with the dome and place the entire tray in warm location with appropriate amount of light. You can also use a heating pad for warmth. I place my clones on top of a T5 and avoid heating pads altogether.
Step 5: MIST, MIST, MIST
Mist your clones periodically to help maintain high humidity and to feed the rooting girls. They can only feed from leaves until their roots develop! I use Superthrive and extremely diluted veg nutes.
A good rule-of-thumb to follow is to always keep a clone. I can’t count the number of times I’ve heard or have exclaimed myself, “I should have kept a clone!” after flowering fine genetics and losing the opportunity to save them in our stable.
In order for your clones to survive, you have to keep their environment at specific levels. You should shoot for these ranges:
Humidity: HIGH from 75%-85%
Temperature: 24 – 28°C/ 75.2°F – 82.4°F (Ideal Temp: 26°C or 78.8°F)
Light: can be measured in two types of energy
- Light intensity (lumen): best under low light levels. High light levels will stress your clones, which is why low-intensity lighting (fluorescent) work best.
- Light color (spectrum): blue light spectrum stimulates vegetative growth. Fluorescent bulbs with 6,400K (blue spectrum) are ideal for clones because of this.
If you properly nurture the rooting clones by maintaining humidity, temperature, and light within ideal ranges, then you should begin to see roots within a week (unless you’re using an EZ Cloner, then that’s a whole other adventure).