In the past I was responsible for cloning rooms that were putting out up to 2,000 clones every 10 days. With this kind of volume it is important to be highly-organized and to have big, solid mother plants that will rebound quickly. Here are some tips when it comes to making cuts; whether or not you are making cuttings on a large scale or on a small scale the rules you will need to follow are about the same. The only difference is upscaling. To start with clones need a very sterile and clean environment. Before using scissors, as an example, always disinfect them and make sure you are using clean, new razor blades.
The idea behind cloning is to take a cutting off of a plant and to get it to root. Once you’ve rooted the clone, you have another identical duplicate of your ‘mom’ to use as you see fit. Cloning can be done in any medium, from rockwool cubes to peat pots. However, try and use a medium that holds water well, as for the first few days your clones will sit under a dome to keep the humidity high. Temperatures should be around 80-82 degrees while the humidity should be up around 70-80%; you don’t want it to get above 90 as you risk that they will rot. It’s also a good idea to heat the bottom of the clones using a heating mat. In fact, they sell kits that include a tray, rooting mat and domes.
Once you have selected your medium, soak it for 24 hours in some type of diluted rooting hormone and pH’d water (pH should be between 5.8-6). You really want the medium hosting the clones to be as wet as possible. The next step is to take your cutting. Always take a cutting at an internode and usually leave about 3-4 internodes of space on the cutting, as you will want to trim it down to the desired size. Use scissors to make your initial cut, and then take all the lower leaves off of the stem. Ideally I’ll hold the top part of the plant and collect the leaves into a bundle, then trim the leaves off to make the surface area of the cutting as small as possible. This tends to give it a better and quicker chance to root.
Once you’ve got a few cuttings, put them into water so that about a third of the bottom of the cutting is submerged. This bit of moisture will protect the cutting by creating a barrier of moisture around where you have made the cut. If air gets into the stem it’s possible that an air bubble will create an aneurysm type of effect and will kill the clone.
Once you’ve collected a few clones you can now take your razor blade and make a diagonal cut on the bottom of the cutting. Try and slice it on a diagonal, as, again, it will make the clone root easier. Next, dip it into a rooting hormone and stick it into your medium. Then cover the tray with your dome and wait a few days. Always check on your cuttings at least once a day to make sure the medium is not dried out; if it is fired out, you can bottom-feed with a diluted root stimulator and pH’d water. Leave the dome on for at least the first three-four days, after the third day you could lift it up slightly – propping it up so that some air gets underneath. After about a week you should see white roots appearing from the base of your medium. The plants are then ready to be transplanted into whatever medium you are using for growing.
Happy cloning and keep on growing!