There are two ways to propagate Jovibarba heuffelii… division and seeds.
First, divison… In Jovibarba heuffelii, the baby rosettes actually grow between the leaves of the mother rosette, eventually forming tightly packed mounds of connected rosettes growing in all directions. To remove an individual rosette for propagation, the rosette (and a portion of the root) must be cut from the mother rosette. I have found that it works well to separate the rosettes using a sharp knife and then to continue the separation by tearing down into the fleshy root.
Jovibarba heuffelii are prolific… every year each rosette can produce up to five or more new rosettes, and all of these new rosettes will be identical to the mother plant.
When the new rosettes have reached a certain size… usually this is when they are two or three years old… they will start to bloom. The center of the rosette will form a thick flower stalk and after several weeks, pale yellow bell-shaped flowers. Over the next couple of months, more flowers will open and seed pods will form. J. heuffelii are monocarpic, so the flowering rosettes die after producing flowers and seeds. (In the photograph below, the rosette at the right is just starting to form a flower stalk.)
Propagating Jovibarba heuffelii by seed… I have found that it is relatively easy to grow new J. heuffelii from my collected seeds. However, because J. heuffelii are hybrids, the new seedlings will not be identical to the the mother plant.