A brief, step-by-step guide to taking stem cuttings (aka clones)
Stem cuttings are by far the most common type of cutting that growers take. It involves removing some stem from a plant that contains a healthy growth tip. For this example, we're going to use tomatoes but you could easily apply this method to virtually all softwood plants.
Step 1 - Take a clean scalpel or a very sharp knife and remove a healthy looking branch from your mother plant. The branch must contain at least one growth tip (i.e. the point from which new leaves and shoot emerge.) The sharper the blade, the cleaner the cut and the less tissue damage around it-meaning less chance of disease.
Step 2 - Remove any excess stem. Many grow guides will tell you to take a cutting at a 45 degree angle, to increase the surface area of the exposed cutting to rooting stimulators. At risk of being contentious, this really is not necessary! I actually prefer to take a 'squarer cut' because the cut part of the stem is less susceptible to damage.
Step 3 - The more foliage on your cuttings, the more 'life' it has to support. It makes sense, therefore, to remove any excessive foliage. Yes, some leaves need to remain but you're really after small, manageable cuttings that aren't going to crowd out your propagator or cloning machine. Trim the tips of larger leaves so that the cutting is no larger than the space it is going to be given in your cloning machine. Less foliage on your cuttings makes life easier because there are fewer leaves for the cutting to support through this acutely stressful period in its life! Just as importantly, small cuttings don't overlap each other so much, which significantly reduces the risk of mold.
Step 4 - Your cutting should look something like this. Most growers aim for cuttings between three and five inches from top to bottom. The next step is to dip your cutting into some rooting stimulator. Though not essential, rooting times will be shorter, decreasing the chance of mold or stem rot. Several compounds can be used to promote the formation of roots. They work by signaling the activity of plant hormone auxins. Among the commonly used chemicals is indole-3-butyric acid (IBA) used as a powder, liquid solution or gel. There are also cloning products on the market that use only natural ingredients. Whichever route you take (pun intended, sorry), don't dip your cutting straight into the jar the product came in as this can lead to contamination and a far less effective product. Instead, pour a small amount into a shot glass and dip into that instead. Clean the shot glass and your blade regularly, particularly if taking cuttings from more than one mother plant. You don't want to be transferring viruses between plants!
Okay, so now you have a freshly-taken, foliage-trimmed cutting, that's been dipped into rooting gel or powder.
It's time to fire up your cloning machine! A timely word of advice: it's important not to dawdle when taking cuttings! Remember, every second counts. After all, if you leave a cutting on your kitchen table, it will dehydrate and be well on the way to dying in a matter of minutes. So the sooner you can get your cutting into a propagator or cloning machine, the better. Preparation is key, especially if you are taking lots of cuttings.