No one ever talks about this, but you can start semps from a leaf. It doesn't always work, but I have done it. I have been fascinated with propagating plants since I was a very little kid. Almost any succulent will start from a leaf, so when I started growing semps, I tried them too.
It's a little tricky with semps, because you have to get the ENTIRE leaf at the base. You need every speck of the leaf tissue that wraps around the stem intact. Depending on the variety, some are easier to take a leaf than others. If any part of the leaf tears and "bleeds green" it won't take, so you might as well toss it. Now, lay leaf on dirt or cactus mix that is BARELY damp. It is best to use a small terrarium or glass bowl, with only an inch or so of soil in the bottom. You have to put the same side up that was up, when the leaf was growing on the plant. This sounds like common sense, but sometimes after you take a leaf it's hard to tell, so lay them out, when you take them. Now, prop the leaf up with a small stone or something, so that the edge of the leaf that was on the stem touches the dirt. Don't cover it up. Now, cover the bowl with plastic wrap and put in a sunny window. It's hard to do outside, because wind blows them, rain washes them away, and they dry out too quickly.
Now, just wait. If it took, you will see small roots come out of the end of the leaf. Then you know you're good. Soon, the teeniest semp you ever saw in your life will form at the base of the leaf. Like I said, it doesn't always work. Some rot almost right away. Some dry up, but some DO TAKE!
And, you really have nothing to lose but a few leaves on a plant that's going to die anyway.
Good luck!
