FWIW, I have semps growing directly on rocks and the only water they ever get is when it rains, Sometimes in summer it will be a month between rains here in MI, yet they soldier on. They are VERY easy to over-water.
Once a semp bolts (starts the bloom to seed cycle), you can stop the bolting if you immediately cut the core out if the center of the rosette. Soon after, you'll get new plants from the nodes immediately below the missing core.
This link might be helpful:
https://mountaincrestgardens.c...
Semps on rocks and on a board:
Black rock in full sun ^^^
Nickel for size perspective. The 3 larger plants are bolting.
Semps in a hypertufa trough:
The kernel of dry corn offers size perspective. The trough is in full sun (had to move it to full shade to get a decent image) and never gets watered. It's growing in the gritty mix with a very few prills of Osmocote Plus.
Al
