Cloning marijuana: how to take successful cannabis cuttings.
For anyone wanting to grow several plants – and certainly anyone using NFT, taking cloning marijuana is probably the easiest method of propagation
Advantages of taking cannabis cuttings:
- no male plants
- plants are the identical strain & breed: they are clones, without variance. All plants mature equally & will be the same size & form, given equal environmental conditions
- cloning marijuana is quicker than growing from seed.
Disadvantages of taking cannabis cuttings:
- Possibility of passing on diseases (and susceptibility to a disease) and pests if they were common in the existing plant;
- Whilst the cost per cutting may appear cheaper than the cost per seed, you will need both more space in the form of a light shielded room kept purely for a plant remaining in the vegetative stage which is often on a different light cycle to your main grow room. This all means more lighting and equipment;
- Keeping a mother plant – and by implication, a cycle system of propagation – can be cited by authorities as evidence of marijuana production rather than a lesser charge of cultivation
Choosing a good mother plant
The best way to get a good mother plant to clone is to take cuttings from a selection of numbered plants grown from seed. Keep these in vegetative growth. Meanwhile as soon as the cuttings have rooted, you need to force them into flower by putting them on a 12 hour light cycle. Once the cuttings begin to show their sex, choose the best female cutting: Remember whilst this process has been happening, its mother plant has continued to grow in your vegetative grow room. This is your best mother plant and you can dispose of the others.
Nitrogen inhibits cloning, so it is important to flush the mother with fresh, pHd water for up to a week before taking the cuttings (your water should have a pH reading of 6.3 if growing in soil, or a 5.8pH if using rockwool).
What do I need to take successful cannabis cuttings?
You will need:
Cuttings medium, such as rockwool (most commonly used)
Sterilizing agent, such as H202, at 3% dilution rate
Thermostatically controlled propagator
A heated propagator provides the ideal environment for seedlings and clones to grow. The thermostat regulates heat to simulate a spring climate, while the vented roof enables you to control necessary humidity. Left in the open air, marijuana clones would suffer from cold and dry air and fail.
Back up block of wood
Rooting hormone – gels are easier
Container of clean distilled water
Before you start:
Pre soak the cutting medium (e.g. rockwool) for 24 hours before taking cuttings. Put in propagator when soaked to warm;
Sterilize a scalpel with H202 , or alcohol;
Prepare thermostatically heated propagator;
Clear and clean workspace
Instructions for taking successful cannabis cuttings:
- Using the scalpel, take a relatively young vegetative side shoot about 2”-4” (5-10cm) long;
- Carefully remove the bottom two leaves, flush with the stem;
- Cut at a 45-60º angle half a centimetre below the inter nodes where you just removed the leaves. Its best to use a back up block of wood to make a clean cut: you must avoid crushing the stem.
- Place the marijuana clone immediately in the water container. This is to avoid embolism which is a pocket of air entering the cutting, causing it to wilt;
- Dip the stem into the rooting hormone, then place immediately into the warm, moist rockwool in the propagator. Gently tamp down the edges of the hole to secure the marijuana clone and ensure that the cut internodes are not exposed but surrounded by the medium;
- Take more cuttings than you need, although as you become adept at it, a success rate of 95% and higher is achievable.
- Mist the cuttings and the inside of the propagator with pHd water (if using rockwool this should be between 5.5 and 6pH). Misting using a fine nozzle water sprayer coats the leaves with an even amount of light water droplets. This keeps the humidity high (ideally it should be around 90%) as the plant is as yet unable to provide itself with water through a root system;
- Lighting is important, use either 2 CFLs placed quite close to the lid (2” or 5cm), a LED system or if using HID, at least 3’3” (1m) distance for up to 400w, 6’5” (2m) for a 1000 watt bulb. Better still, use fluorescent CFLs as these reduce the chance of stretching. Set the period of light is as for vegetative growth, i.e. 18-24 hours a day;
- Check the marijuana clones regularly for the first few days. Control humidity using the vents and mist if required. The marijuana clones should never be allowed to dry out, but a common mistake is to over water which prevents oxygen getting through the rockwool. Use either a specialist cuttings food or a quarter strength vegetative cannabis feed as the cloning medium contains no nutrients. Maintain a good root temperature of 72ºF – 79ºF (22 – 26ºC);
- Five days to two weeks later, open the propagator vents to release humidity. If the clones show no sign of wilting, start to harden off by gradually exposing them to life outside the propagator, keeping humidity at around 70%. Once the clones have rooted, stop the misting process as this can lead to rot.
Clonex CLO100 Rooting Compound Gel, 100ML
Hydrofarm CK64060 Hot House with Heat Mat
Essential Oxygen+ Hydrogen Peroxide 3% Food Grade 16 oz
Disposable Scalpels #10 Miltex (Box of 10)
Grodan A-OK 1.5″ Starter Plug, Sheet of 98