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The common names and history of Sempervivum are as interesting as the plant itself. Translated, Sempervivum means “always living,” or the common name of live forever. A common European name, derived from the practice of growing them on rooftops, is houseleek. In the United States they are most commonly known as hens and chicks, though they are sometimes called cats and kittens or even old man and old woman.
Sempervivums are hardy alpine succulents in the Crassulaceae family. In their natural habitat, they are usually found 3,000-8,000 feet above sea level in the mountainous regions of Central and Southern Europe and Mediterranean Islands. |
As mentioned previously, in some places Sempervivums were/are grown on rooftops, between the thatching, tiles or timbers. In ancient times, they were thought to guard against thunderbolts, storms and sorcery, and to ensure the prosperity of the occupants. There is now a company in Germany that exports them as rolls of carpet or roofing material. They even had an exhibit at the 2003 Chelsea Flower Show.
Though it is not recommended to use Sempervivum for medicinal purposes, it did hold a place in traditional medicine. The Romans considered the juice to be useful in protecting crops from caterpillar infestation.
There are approximately fifty species and over 6,000 named cultivars of Sempervivum. They vary in color, texture and size. Colors include green, silver, deep maroon, brilliant red and many shades and combinations in between. While some are smooth to the touch, others are velvety or even look as though they are covered in spider webs (Sempervivum arachnoideum). Their size ranges from one-quarter of an inch to thirteen inches in diameter! Sempervivums are related to Jovibarba and Rosularia and are distinguished by their flowers.
Sempervivum care is easy, but the key is that they thrive on neglect. They will live much longer if carelessly thrown on concrete and forgotten than they will if planted in rich, organic soil and well watered. In fact, I took such good care of my first Sempervivums that I killed them almost immediately. Fortunately, the source of my first ones had a plenty more to share. Since they were doing so well at her home, I planted the second batch in a similar setting … the driest location with the worst soil. They thrived. The three things to remember when growing them are that they prefer full sun (a little afternoon shade may be useful), well drained soil, and very little water. They can easily be grown in cracks in dry stone walls, hypertufa, troughs, rock gardens, or a poor soil area that does not hold water. Very sandy clay soil is ideal. They can also be used to make living wreaths.
Though most will do just fine outside over the winter, some Sempervivums are a bit more susceptible to the cold and wet. Those with webbing or a velvety texture are most at risk. Since I like to have some in pots anyway, I take a start of each into the garage to overwinter. My garage is not attached or heated, but at least they are dry, and the wet is more likely to kill them than the cold.
Many people are surprised to see their Sempervivums bloom. It takes three or four years for it to bloom, and the bloom is its last hurrah before it dies. Since the babies grow so quickly, the hole it leaves is soon filled in. Since the bloom was said to “resemble the beard of God,” they were considered sacred to Jupiter in Roman and Thor in Nordic mythology. The word Jovibarba is from the Medieval Latin, Jovis barba, which means, “beard of Jupiter.”
Mostly Sempervivums propagate by sending out offshoots, which root and become independent of the parent plant as the connecting stolon withers. Offshoots can be moved once they have reached a sufficient size. The stolon should be cut off at approximately one-half inch from the base of the new plant. This encourages roots to develop at the base of the rosette instead of along the stolon. Push the stolon into the soil, leaving the baby to sit on top of the soil.
Sempervivum heuffelii differs in that to propagate it, you must cut the babies from the mother plant, making sure to get part of the root, or it will not survive. The babies of Sempervivum sabolifera are sometimes referred to as “rollers,” as bumping them will dislodge them and they roll from the mother plant. However they land, they root, and as they grow, they right themselves.
If you are feeling more adventurous, Sempervivums can also be propagated by seed. When pollinated, the flowers produce star shaped fruit that can be collected, allowed to dry, and the seeds removed. Stratification aids the seed germination. Since cross-pollination frequently occurs, seedlings are not likely to be true to type.
Sempervivums have their best color in the spring, and if the weather is right, in the fall. They can easily rival a flower! The main factors of color are light intensity and day length. The soil’s fertility, pH, moisture and structure, as well as the temperature and age of the plant (some take up to three years for full color) also effect coloration.
Fortunately it is getting easier to find showier cultivars of Sempervivum in garden shops, though the best selection is probably still at online specialty stores. The company I purchased most of mine from several years ago is North Hills Nursery, and if the quality is the same now as then, I highly recommend them. If the reason you do not grow Sempervivum is because they are so plain, maybe it is time you looked again.
Sadly, in an exceptionally rainy year, a beautiful and even well established Sempervivum garden can be lost.
Though it is not recommended to use Sempervivum for medicinal purposes, it did hold a place in traditional medicine. The Romans considered the juice to be useful in protecting crops from caterpillar infestation.
There are approximately fifty species and over 6,000 named cultivars of Sempervivum. They vary in color, texture and size. Colors include green, silver, deep maroon, brilliant red and many shades and combinations in between. While some are smooth to the touch, others are velvety or even look as though they are covered in spider webs (Sempervivum arachnoideum). Their size ranges from one-quarter of an inch to thirteen inches in diameter! Sempervivums are related to Jovibarba and Rosularia and are distinguished by their flowers.
Sempervivum care is easy, but the key is that they thrive on neglect. They will live much longer if carelessly thrown on concrete and forgotten than they will if planted in rich, organic soil and well watered. In fact, I took such good care of my first Sempervivums that I killed them almost immediately. Fortunately, the source of my first ones had a plenty more to share. Since they were doing so well at her home, I planted the second batch in a similar setting … the driest location with the worst soil. They thrived. The three things to remember when growing them are that they prefer full sun (a little afternoon shade may be useful), well drained soil, and very little water. They can easily be grown in cracks in dry stone walls, hypertufa, troughs, rock gardens, or a poor soil area that does not hold water. Very sandy clay soil is ideal. They can also be used to make living wreaths.
Though most will do just fine outside over the winter, some Sempervivums are a bit more susceptible to the cold and wet. Those with webbing or a velvety texture are most at risk. Since I like to have some in pots anyway, I take a start of each into the garage to overwinter. My garage is not attached or heated, but at least they are dry, and the wet is more likely to kill them than the cold.
Many people are surprised to see their Sempervivums bloom. It takes three or four years for it to bloom, and the bloom is its last hurrah before it dies. Since the babies grow so quickly, the hole it leaves is soon filled in. Since the bloom was said to “resemble the beard of God,” they were considered sacred to Jupiter in Roman and Thor in Nordic mythology. The word Jovibarba is from the Medieval Latin, Jovis barba, which means, “beard of Jupiter.”
Mostly Sempervivums propagate by sending out offshoots, which root and become independent of the parent plant as the connecting stolon withers. Offshoots can be moved once they have reached a sufficient size. The stolon should be cut off at approximately one-half inch from the base of the new plant. This encourages roots to develop at the base of the rosette instead of along the stolon. Push the stolon into the soil, leaving the baby to sit on top of the soil.
Sempervivum heuffelii differs in that to propagate it, you must cut the babies from the mother plant, making sure to get part of the root, or it will not survive. The babies of Sempervivum sabolifera are sometimes referred to as “rollers,” as bumping them will dislodge them and they roll from the mother plant. However they land, they root, and as they grow, they right themselves.
If you are feeling more adventurous, Sempervivums can also be propagated by seed. When pollinated, the flowers produce star shaped fruit that can be collected, allowed to dry, and the seeds removed. Stratification aids the seed germination. Since cross-pollination frequently occurs, seedlings are not likely to be true to type.
Sempervivums have their best color in the spring, and if the weather is right, in the fall. They can easily rival a flower! The main factors of color are light intensity and day length. The soil’s fertility, pH, moisture and structure, as well as the temperature and age of the plant (some take up to three years for full color) also effect coloration.
Fortunately it is getting easier to find showier cultivars of Sempervivum in garden shops, though the best selection is probably still at online specialty stores. The company I purchased most of mine from several years ago is North Hills Nursery, and if the quality is the same now as then, I highly recommend them. If the reason you do not grow Sempervivum is because they are so plain, maybe it is time you looked again.
Sadly, in an exceptionally rainy year, a beautiful and even well established Sempervivum garden can be lost.
Sempervivum ‘Cobweb Buttons’
hardy in zones 3-8 July bloom New to our garden. As yet, I can't see any difference between this and 'Cobweb Joy'. |
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Sempervivum ‘Dolle Dina’
hardy in zones 4-10 June-July bloom |
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Sempervivum ‘Ginnie’s Delight’
hardy in zones 4-10 June-July bloom |
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Sempervivum ‘Glowing Embers’
hardy in zones 4-10 |
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Sempervivum ‘Gold Nugget’
PP 28284
perennial in zones 3-8
New to our garden in 2019.
PP 28284
perennial in zones 3-8
New to our garden in 2019.
Sempervivum ‘Granada’
hardy in zones 4-10 July-August bloom |
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Sempervivum ‘Koko Flannel’
hardy in zones 4-10 June-August bloom |
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Sempervivum ‘Pacific Blue Ice’
hardy in zones 3-8 New to our garden in 2016 and still establishing. |
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Sempervivum ‘Purple Beauty’
hardy in zones 4-10 June-July bloom |
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Sempervivum ‘Pyrenaicum’
hardy in zones 4-10 July bloom |
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Sempervivum ‘Red’
hardy in zones 4-10 July-August bloom |
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Sempervivum ‘Red Rubin’
hardy in zones 3-9 June-July bloom |
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Sempervivum ‘Ruby Heart’
hardy in zones 3-8 |
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Sempervivum ‘Silverine’
hardy in zones 4-10 July-August bloom |
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Sempervivum ‘Silver King’
hardy in zones 6-11
August bloom
hardy in zones 6-11
August bloom
Sempervivum ‘Twilight Blues’
hardy in zones 5-9 July bloom |
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Sempervivum arachnoideum ‘Cobweb Joy’
hardy in zones 5-8 June-July bloom |
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Sempervivum x barbulatum ‘Hookeri’
hardy in zones 5-8 |
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Sempervivum sabolifera
hardy in zones 4-10 |
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Sempervivum tectorum
hardy in zones 3-11 |
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Updated March 24, 2022.