There’s a lot of ways to effectively clone; so I would never say my methods are the best. I would - however - say my recipes are reliable and produce amazing results! In this quick article I focus on the anatomy of an ideal cutting based on personal experience operating a company focused on cutting propagation. Some of you may already know I've spent years playing with different recipes and methods to cloning. This article is about my favorite style cutting, specifically.
Mother plants need to have a lime-green color, not dark blue-green (i.e. over-fed). You want parent plants fed at exactly the amount of nutrients needed to avoid deficiency, and no more. In coco- and peat-based mediums I recommend feeding moms in the 400 - 600 ppm (EC: 0.8 - 1.2 mS) range, not including cal/mag or hard-water readings. This has to do with organic mediums' nutrient buffering capacity. In Aeroponics or Deep-Water Culture (DWC) you can use half these values (200 - 300 ppm, EC 0.4 - 0.6 mS, again not including cal/mag or your water's base reading). This is because water culture doesn't compete for mineral nutrients like organic-based growing mediums. Water culture doesn't buffer your nutrients.
Just before placing in the cloner, take a final cut a few millimeters above your initial cut and aim for an obvious "plug" of xylum and carbohydrate (accessible sugars) as shown above. The one shown, sadly, went dry as I was trying to take pictures, but a fresh cut should look wet and immediately placed in your sterilized propagation system. Sometimes this "plug" is more white, others have a fleshier, light-green core. The goal is to avoid a hollow section exposed. For strains with hollow stems, the plug will usually be found just below the nodes.
Check out our publication: PermaClone™ Manual for Perfect & Predictable Hydroponic Cloning for a thorough out-line of recommended methods to cloning and sterilizing your system.