I am familiar with the Echeveria (and its allies) leaf cuttings propagation. Normally, when the leaf calluses it can be inserted into the potting medium and be given enough time to root and sprout a new bud. However, the lady in this video seems to use another variation of this method as shown in this YouTube video here:
She plucks out the leaves and tosses them on the floor to callus and form the rosette. She takes a different path after the new bud forms a rosette large enough to plant. She plucks it out and inserts it into the potting medium without the leaf from the mother plant. In this video, I can see that the rosette has no roots yet. I may have seen one with roots, but most don't have any. I know that the leaf should be kept to feed the rosette until it shrivels and is removed only when it has done its share and dried up. This method may save space in the rooting tray, but there are two "weak links" to consider in the chain of events:
The leaf from the mother plant has not given out all its water and nutrient content to the rosette
the rosette is severed and planted immediately in the rooting tray, without giving it time to callus, therefore increasing chances for basal rot. On the other hand, letting it callus once again is an extra step that requires extra time and energy, all without having new roots ready.
So, is the method in this video practical? Is the sheer number of cuttings used this way what compensates for the lower success rate?