House Leek, Hens-and-Chickens, Jupiter’s Beard, Etc.
Sempervivum x ‘Killer’
Sempervivum tectorum Hybrid
Sempervivum tectorum L. is the correct and accepted scientific name for this species of Sempervivum. The genus and species were described as such by Carl von Linnaeus in the first edition of Species Plantarum in 1753.
As of 11-20-21 when this page was last updated, Plants of the World Online by Kew lists 52 species in the Sempervivum genus. it is a member of the plant family Crassulaceae with 36 genera. Those numbers could change as updates are made on POWO.
THERE ARE A FEW LINKS AT THE BOTTOM OF THE PAGE FOR FURTHER READING.
I brought this really nice Sempervivum Hybrid ‘Killer’ home from Green Street Market, a garden center in Clinton, Missouri, on April 24, 2018. They always have a great selection of plants and sometimes it is hard to choose. I put it in the old cast iron planter beside the bed behind the old foundation. The cast iron planter used to be part of an old coal-fired furnace a good friend and I removed from a home in the early 1980’s.
Sempervivum tectorum forms broad, rosette-forming clumps that spread by offsets. Mature plants develop broad, flat, pointed leaves that are sometimes suffused with red. Carl Linnaeus’s description in 1753 in Species Plantarum says “its leaves are ciliate, that is. fringed with hairs.”
This Sempervivum cultivar was hybridized and registered by Volkmar Schara of Germany in 2004. According to one website, they are also sold under the name of Chick Charms® ‘Cranberry Cocktail’. That name led me to the Chick Charms® Collectable Hens & Chicks website. I visited the site before but as I am writing this post my iMac won’t let me go to the website… They do have a Facebook page, though. One of the Amish greenhouses usually had a good-sized selection but they relocated.
Chick Charms® are selected by Chris Hansen who is also the breeder of SunSparkler® Sedums. He has a collection of over 485 named varieties (when I first wrote this page in 2017). Many of the listed cultivars were re-named so they are the same as other named cultivars…
You know, there are over 4,000 named cultivars of Sempervivums and SO MANY of them look exactly alike. No doubt many are the same and the result of the same crosses or sports. Just like in this case… They were hybridized AND registered under the name ‘Killer’ and they are also sold under the Chick Charms® name ‘Cranberry Cocktail’.
Origin: The species are native to the mountains of southern Europe.
Zones: USDA Zones 3-8.
Size: At least 2-3” tall.
Light: Sun to part shade.
Soil: Very well-drained. If grown in pots, use a quality potting soil amended with pumice (50/50) or additional pumice and chicken grit.
Water: Average during the growing period, barely in winter.
Information online says that Sempervivum grows well in full sun to part shade. In my experience… It is best to keep your Sempervivum where they at least have afternoon shade. As you can tell in the above photo, they are NOT all that heat-tolerant during the hotter months of the summer. I got busy and kind of neglected the beds for a while and the next thing I knew some of the plants, including the Sempervivum x ‘Killer’ were having issues…
This plant grows fast during the spring and then starting again in September. I think they are probably summer dormant as many members of the Crassulaceae family. They aren’t listed on my dormancy table, though.
Sempervivum tectorum has been popular for at least 200 years. The Romans believed they protected buildings against lightning strikes which is one reason they are popular as roof-top plants. It was also believed they protected the occupants against sorcery and ensured their prosperity. Well, there were other reasons for using them on roofs including they helped preserve thatched roofs and helped to prevent fires (or at least its spread). The Wikipedia article about this species says it has been known to humans for thousands of years…
The species name, tectorum, means “of the roofs of houses”.
Being grown for so many years has led to its many common names. One of the most interesting is “Welcome home husband, however drunk you be”.
There were also many medicinal uses for this plant which you can read about from a few of the links below.
We had a very cold January and the temperature dropped to -10 degrees F a few times during the first week. We didn’t have much snow over the winter which can be hazardous for many perennials that need protection. While some plants completely disappear over the winter, the Sempervivum ‘Killer’ went through it all with flying colors.
By the time the above photo was taken on April 8, we were having a steady warming trend. This Sempervivum is really looking AWESOME with its multi-colored leaves.
Sempervivum ‘Killer is doing quite well and starting to send out new offsets.
By June, as the temps start heating up and rain is seldom, the Sempervivum ‘Killer’ may be in kind of a dormant phase. It’s leaves are mostly green now…
Sempervivum tectorum multiplies by offsets which they start producing at a young age. Once the parent plant flowers and sets seeds, it will die, leaving behind many young. By the end of June, this cluster is once again growing. Well, it seems to take spurts…
While taking photos on July 29, I saw the Sempervivum ‘Killer’ was starting to flower. I’m not sure when it started because I got busy with other things and hadn’t been paying much attention.
I was glad it was flowering because this was the first Sempervivum I had grown that had produced flowers.
The next thing I knew, another cluster of buds was forming…
It is kind of sad, though, because when it is finished flowering, the rosette will die…
The flowers are, to say the least, very interesting…
Several of the larger rosettes have flowers and buds and there is a multitude of offsets on the backside of the clump. It’s like the cycle of life unfolding right before my eyes.
We made it through the winter with flying colors. It wasn’t as cold as last winter and there many nice days followed by snow on several occasions. The larger Sempervivum ‘Killer’ rosettes flowered leaving behind several plants that need to be discarded.
While I was taking photos on March 24 I decided to go ahead and clean up the Sempervivum ‘Killer’ and replant the rosettes. The one in the center-left may have been one of the rosettes that flowered, so it may not last. It seems there were more young offsets last summer but a total of 15 is all I came up with. Now we shall see how well they do. I don’t care if they flower or not since they are monocarpic and will die afterward.
Getting off to a great start by April, 7 in 2019 when the above photo was taken.
Looking AWESOME by May 5.
I am running out of words…
Still doing great in May 19. The Phedimus kamtschaticus ‘Vargiegtum’ next to it is beginning to bud.
The above photo was the last I took of the Sempervivum ‘Killer’ in 2019. Luckily it didn’t get any ideas from the Phedimus and flower. We don’t need the Sempervivum to bloom…
The Sempervivum ‘Killer’survived the winter and did OK throughout the summer. I was fairly busy with the garden and didn’t take many plant photos in 2020.
Sempervivum are very easy to grow and they only have a few rules. The most important is their soil and water. They need a very well-draining soil and raised beds are very good for that reason. They are great in containers in potting soil amended with extra grit and pumice or perlite. For succulents in pots, I used 2 parts Miracle Grow or Schuultz Potting soil amended with 1 part chicken grit (from the feed store) and 1 part perlite for many years. Many cactus and succulent growers and collectors recommend pumice over perlite. Sempervivum isn’t especially fond of a peaty mix because it holds water which is why it needs to be amended. Sand shouldn’t be used unless it is very course because it fills up the airspace in potting soil. I switched to using a 50/50 mixture of potting soil and pumice in 2018.
They appreciate regular watering during the summer, but not in the winter. Of course, they understand mother nature and we can’t control what she does. For that reason, if you overwinter your Sempervivum outdoors, they need to be in a location where drainage is adequate. If you grow them in pots, they require very little water during the winter, if any at all. It just depends on where you keep them. Believe it or not, I have successfully overwintered several Sempervivums in the basement where they did very well in low light and hardly ever gave them water. The temperature stayed around 65 degrees.
I will continue adding more photos and information as time goes by.
I hope you enjoyed this page and maybe found it useful. If you have any comments, questions or suggestions, I would like to hear from you. Please click on “like” if you visited this page. It helps us bloggers stay motivated. 🙂 You can check out the links below for further reading. The links take you directly to the genus and species of this plant.