How to prevent Sempervivum tectorum (Common Houseleek) from growing in length and not width?

Question

I have torn a part of this plant twice at my hometown, brought it to where I live now and then planted it. On both occasions, the plant started growing fine at first, but at some point, it started extending its stem and growing in order to reach the sun as much as possible (the top level entirely left the pot). What happened next in both occasions is that the old leaves at the stem started falling off and eventually the stem rotted, dividing the healthy top of the plant from the root.

I've tried replanting the leftover in the first case, but it eventually died off. Currently, I have the leftover of the 2nd plant which I tried replanting, but don't know what will happen yet.

I'm keeping it inside my office. It's facing east. During the morning it's very sunny, but in the afternoon it's not. I water it once per week, or once per 2 weeks.

Question: What do I do with this plant once it starts growing in length rather than in width and how can I prevent that? Is the problem that I have it inside the apartment instead of outside?

I'm trying to get it to grow and look like the picture on the left, but mine looks like the one on the right.

Answer 1

Disclaimer: I've never planted a Sempervivum. This is just my guess.

From the information about Sempervivum on this page:

The hens will die after flowering, but by that time they will have produced numerous chicks or chickens to take their place. Reproduction is normally vegetative by cutting the numerous stolons growing near the main rosettes. To propagate, simply split off the chickens from the parent plant and transplant them. Providing contact with the soil should be sufficient for transplanting, since sempervivum root readily. The powdery seeds are used to produce particular hybrids.

From your 2nd picture, I can see it is flowering. Flowering may weaken the plant, as it consumes a lot of nutrients (this is true of most flowering plants). You may want to make sure that you don't water it too much, as this will only make it weaker.

According to this:

Sempervivum can be grown in a place with full sun to partial shade and in well-drained soil, so is the perfect plant for hot, dry, sunny locations. Though they can adapt to a variety of soil types, they will do best in gritty soil. No particular care is required, but the plant will grow too much, making it weak and subject to rotting, if there is excessive watering or use of fertiliser. They suffer in hot summer weather, especially if there is much humidity.

If you search Google images for "Sempervivum flowering", you will a lot of pictures similar to yours, but their flower stalk is upright. However, yours is creeping, and I might consider this is an indicator of bad health. May be it's not getting enough sunshine. Can you move it outside? Good luck.

Answer 2

It's flowering. Sempervivums are monocarpic so when they flower they die. However they usually form so many offests that the exponential population growth makes up for it. Weak looking rossettes are almost always the result of a lack of sunshine.

Don't fertilize them and make sure they have gritty high drainage potting compost and that pots have holes and are not sitting in saucers

Answer 3

Sempervivum is not a houseplant!

The "problem" you describe is called flowering :) Once starting to flower, the rosette starts to grow upwards (in your case sadly sidewards & downwards which shows the unfavourable conditions plant was growing in!). Afterwards, the flowering plant dies, and this is normal.

Here's more on Sempervivum cultivation on my website.

Answer 4

It needs cold weather during the year. Indoor conditions all year will eventually kill the plant (or colony). It's a zone 4-8 plant.