What are the advantages of cloning?
Cloning is the process of making an exact copy of a living thing, in this case a marijuana plant. Cloning has many advantages to offer the advanced grower. First, the process of germination can be skipped over, saving valuable time. Second, the exact genetics of your best female can be preserved forever. Third, growers will save money by not having to purchase seeds every year. For SOG growers, cloning is a must to ensure that only females will be grown and no space is wasted on males. It is advisable to note however that over time if the same marijuana plant is continued to be cloned, it may degrade, become less potent or more unstable. This will only happen once you have cloned the same marijuana plant several times.
For the easy way to clone marijuana, see rooting with rockwool below.
What do I need to start cloning?
To begin cloning marijuana you will need a mother plant. A mother plant is the plant all of the cuttings will be taken from. It should exhibit qualities such as fast growth, high potency and mould and pest resistance, or just be a strain you want to keep growing. The mother should be kept in vegetative growth all the time under a metal halide (MH) light. Other things that will be needed are small plate, a shallow tray that will hold about three inches of water. An aquarium air pump, rooting hormone and high P fertilizer. Light will be provided by fluorescents hung seven inches above the plant tops. An alternative and perhaps easier method involves using rockwool. We will explain that later.
First set the tray in a separate area from all the other plants. A separate closet or basement is good. Fill the tray with water (boiled for 20 minutes) mixed with liquid rooting hormone. Install the aquarium air pump to oxygenate the water. The size of the pump depends on the size of the tray. Make an anti-siphon loop in the hose to the pump to prevent water from getting into it if the power should go out. Next, hang the fluorescents about 12 inches from the top of the tray. This will leave about 7 inches from the tops of the cuttings to the lights.
Taking the cuttings
Once the cloning area is set up the clones can be taken from the mother plant. Taking clones is almost the same as pruning, so when you prune, instead of throwing away the cuttings they can be made into clones. The first cut should be made with sharp scissors or a razor blade sterilized with rubbing alcohol. The cutting should be about 6 to 8 inches tall. Next, trim off the bottom leaves with a sharp razor blade. There should be three or four sets of leaves remaining on the cutting. Bring the cutting to the rooting tray and get out the Styrofoam plates. Poke a hole in the middle just big enough for the stem to fit through. The cutting can be secured in place with some sticky tack (looks like gum). Now submerge the bottom of the the cutting and make another cut diagonally. This will expose more stem surface to the water and make it easier for the cutting to absorb nutrients. This cut must be made under water to prevent a bubble forming in the stem, blocking nutrient intake.
Rooting the cuttings
Now that the cuttings are floating in the rooting tray the water needs to be changed every other day. Just siphon it out and replace it quickly with new hormone treated water. Be careful never to drain all the water out. If the stem bottoms are exposed a bubble will developed inside the stem and the clone will die. After about 10 days in the rooting tray, the stem bottom will start to come out slightly. This is the first sign that the roots will appear shortly. Foliar spray with a chemical fertilizer that is high in P at 1/4 strength every three days. Remember to spray the plants the day after foliar feeding with water to clean the leaves of any un-absorbed nutrients. Soon the tiny immature roots will be visible and when they reach about one inch in length they can be planted in the soil and will grow as an exact copy of the mother plant.
This method is basically the same, after taking the cutting dip in the rooting hormone and place cutting straight into a piece of wet rockwool. The rockwool cubes are kept in a damp tray (must be kept damp but not flooded), cuttings are placed under a fluorescent light (20 hours a day) and kept damp (no nutrients). After around 2-4 weeks, roots will appear from the bottom of the cube. The plant is now ready for transplant.
Also check out these pictures they may help aswell.