Hey, I am new to Sempervivums and plants in general, but picked up a Sempervivum Arachnoideum "Arctic White" and am inlove with these plants.

From my own research, it seems that hybrids like mine can only reproduce via offsets, and not from their seeds because the seeds they produce would only be from the mother species. If this is the case, what should I do when the time comes that they flower? I don't want a bunch of "standard arachnoideums" germinating in my collection. Is this how it works? Will they only produce seeds when you physically cross pollinate them? Thanks!

Hi anteater, nice to me you. And a big welcome to NGA.
That is correct, when they bloom and set seed the seed will not be the same as the parent plant. If you don't want seedlings coming up everywhere just cut the bloom stalks off when the flowers are finished. They are a great source of food for all the different bees, ect.
If you decide to make your own cross between your cultivars you can save the seed and plant them in smaller containers in early spring.
Nice webbing on your 'Arctic White'.
What part of the country do you live in?

Thankyou for the welcome. I am in the NJ area. I've had them outside the last few weeks after separating a few rosettes. Hopefully I will be able to get my hands on a few other kinds!

I'm guessing that this year or next, I will have 1 stalk from the center. If there is only 1 stalk, would it even be possible for the flower to create seeds? Like self pollination? Sorry if it is a very basic question.

Questions are always welcome here. All of us are constantly learning.
They are easily pollinated by the bees.
They usually live for 3 to 5 years before blooming. But, growing conditions can sometimes make them bloom sooner. Hopefully the rosette will have sent out many offsets to take her place.

anteater295 said:

If there is only 1 stalk, would it even be possible for the flower to create seeds? Like self pollination?

Yes, they can be self pollinated. I had one bloom last year when none of the others were blooming, let the bees pollinate it, and now I have some seedlings from it.

Anteater,
Arachnoideums tend to produce less viable seed than other species, particularly the smaller ones which are often diploids (I imagine 'Arctic White' is one of those). Their seedlings also have a tendency to be less varied than other sorts, likely as a result of the arachnoideum blooms occurring before other semps; there seems to be less genetic variation in them, and the closer to a true species a plant is the less variety you seem to get in the next generation. All that said, no rules seem to be set in stone for sempervivum seedlings, if you have a passion for the webby kinds and would be happy to select on for subtle variations in the seedling's size, offset production and color I'd say go for it. But if you want to see more variety than that I'd wait until you had something else to cross it with. And who knows, maybe you're neighbors have something interesting blooming at the same time that the bees can bring pollen over from.
-Sol