This question keeps coming up and I've described this procedure in multiple posts, but they keep getting lost in all the other info. So, here it is again, in its own post, to make it easier to follow.
Ok, so you have a prized rosette that has not yet produced offsets. It's the only one you have or you are not sure the others of its kind are going to survive for whatever reason. You want to preserve it. But its crowning (starting to flower). What do you do?
First of all, do not panic. Many semps will produce offsets on the flower stalk,
but that is not a guarantee.
1) The earlier you catch the flowering process, the better this procedure will work.
2) Practice this procedure on something you have a lot of before you need to use it to preserve a prized rosette.
3) Break off the flower stalk near the level of the normal rosette. Be careful to not damage the rosette itself. A pair of scissors works best. You can plant the flower stalk if you want - it just might make an offset or few before dying.
4) Dig the rosette and remove excess soil.
5) Clean the rosette, washing dirt from the roots and rosette, so that you can clearly see the rosette and roots. Be sure to air dry sitting on an absorbent towel or paper towel.
6) Using a sharp knife, cut the rosette in half, down thru the stem and roots, into two equal parts. I call this a vertical division because it is parallel to the direction of the stem in the direction the plant grows. If the rosette is large and you can assure a root piece on each division, you can further divide the pieces into quarters. (4 total pieces of the rosette). The larger the division, the better it will survive, but also the more likely you will end up with a continued bloom.
7) You
must dry the pieces out of the sun for several days.
8) Plant and label each piece, preferably in a separate, small pot.
9) Place planted pieces in a spot that gets good, strong light, but no sun.
10) After planting, be sure to daily mist the pots so that the surface of the soil gets darkened by the water, but will dry out before the next day. This will help avoid rot, but some regular water is important to promote growth and prevent the pieces from totally drying out.
If you follow this procedure, each piece of the plant will regenerate a rosette. Each of the rosettes will be set back considerably. One of the pieces will likely still bloom, but the other piece(s) will likely not bloom and will produce offsets. Offsets will likely appear a year or two after the surgery.
I want to note here that this procedure, before the appearance of a flower spike, is a way of reproducing or increasing the number of plants you have. You can use it to propagate the slow-increasers in your collection or to propagate those varieties that do not produce offsets on their own.
As a caution, you should keep in mind that without proper care or good technique on the divisions, you can easily kill the pieces of the rosette before they regenerate. So check them daily and adjust the care appropriate to what you see. Be sure to practice this on various sized rosettes before you actually need to do it.
Here's a picture of S. Red Beauty showing a vertical division. You are looking at one half of the rosette on the left side and two quarters of the rosette on the right side.
The plant was further divided as the tag indicates, taking the division to the extreme. Several of these pieces died, but most survived. Good aftercare is essential. I would not divide a rosette you want to preserve to this extent - this was an experiment to see how far I could divide a rosette.
