Sempervivums (Hens & Chicks)

Four summers ago one of my very ordinary green sempervivums produced some rather extraordinary flowers. This sempervivum was a very small rosette, but the flower clusters were unusually large… and although most of the flowers were the usual pink, a few flowers had a definite bluish-purple tone.

There was a package in our mailbox today and it was the best kind of surprise. When I saw the return address, I guessed (hoped) what might be inside… the package was from a long time reader who loves plants, gardening… and especially sempervivums… as much as I do.

If you’re new to growing sempervivums (commonly called hens and chickens)… the flowers, and especially the flower stalks, can come as somewhat of a shock. If you know what to look for, it is usually obvious when a rosette is about to flower… first it becomes larger than the surrounding rosettes, then a fleshy stalk starts to grow out of the center of the rosette. Eventually clusters of small buds form at the top of the stalk. Sempervivums are monocarpic, which means that after the flowers open and fade, the original rosette dies.

I have had sempervivum growing in my gardens for many years, and they are one of my very favorite plants. Often called houseleeks or by the more common name of hens and chickens, these hardy perennials have thick, fleshy leaves and grow in rosettes. Many people grow sempervivum in dry, sunny locations because they require so little moisture, but I have also had great success and much larger plants when I grow them in regular fertile garden soil.

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 taken hundreds and hundreds… maybe even thousands… of pictures of my sempervivums. Some day (hopefully) I will get them all organized according to name. Right now, though, I thought I would share some photographs of my sempervivums in their bright spring colors. I must especially like the red tones, because I have so many in this group. Here are just a few…

These are cobweb houseleeks (sempervivum arachnoideum). The rosettes appear to have small spiderwebs on them, but the “webs” are actually a naturally growing part of these amazing little plants.

Recently several readers have written to me because the tubes of their Oddity are no longer tubes, and they suddenly have a sempervivum with broad flat leaves. They are concerned that their Oddity is reverting back to a non-tubular form. I think their plants might just be adjusting to the colder temperatures.

It’s difficult for me to choose one sempervivum as my favorite (except for Oddity, of course… that is always number one) because each one is special in its own way. However, Purdy’s 70-40 has to be near the top of the list.

Oddity is usually classified as a large sempervivum and a mature rosette can have an astounding number of tubular leaves. I have counted as many as seventy-five tubes on one rosette. Oddity leaves are thick with sharp points and they curl lengthwise and backwards to form the individual tubes.