Sempervivum Tectorum [sem-per-VEE-vum, tek-TOR-um] is a flowering Sempervivum plant species from the family Crassulaceae.
While the plant is native to southern Europe, it is cultivated in the entire continent due to its unique appearance and traditional beliefs attached to it.
For example, in the Roman tradition, the plant is believed to protect buildings from lightning strikes – many of the plant’s common names reflect this belief.
Known to humans for thousands of years, Sempervivum Tectorum goes by many plant names, the most famous and widely used of which is Common Houseleek.
William Thomas Fernie, the author of Herbal Simples Approved for Modern Uses of Cure, shares a story to describe the hardiness of houseleek.
In his book, he narrated:
“A botanist tried to dry a houseleek plant for his herbarium for eighteen months but failed.
He then replanted the houseleek to its original site where it started growing again as if there had been no interference in its regular life.”
Sempervivum is also Latin for ‘live forever.’
Other common names of sempervivum tectorum are:
- Roof houseleek
- Roof foil
- Red-leaved houseleek
- Devil’s beard
- Bullocks beard
- Jove’s beard
- St. George’s beard
- Thor’s beard
- Poor Jan’s leaf
- Healing blade
- Jupiter’s eye
- St. Patrick’s cabbage
- Hens and Chicks (a name it shares with many other species of the Crassulaceae family)
Sempervivum Tectorum Care
Size & Growth
Houseleek is an evergreen, perennial, and low growing succulent plant forming thick and large rosettes of green leaves, which sometimes have purple-colored tips.
The plant is easy-to-grow, hardy, and long-lasting.
Flowering and Fragrance
The mother rosette of roof houseleek grows about a foot long, upright leafy stalks over which the cymes of red-purple flowers bloom.
Light & Temperature
Thunderplant thrives in full sun at a moderate temperature but provide partial shade for the plant in extreme heat.
While temperature fluctuations do not damage the plant, it goes into a semi-dormant state when the temperature rises above 75° degrees Fahrenheit (24° C) or falls below 65° degrees Fahrenheit (18° C).
USDA hardiness zone 3 – 11.
Watering and Feeding
Since hens & chicks is a succulent plant, it doesn’t need to be watered every day.
The best way to water this plant (or any succulent plant) is to water it generously once, so much so the soil is completely soaked and the water starts to come out of the drainage hole (in case of a potted plant).
Then leave the plant on its own and do not water again until the soil has completely dried out (it may take a week or even two depending on the climate).
As a general rule, remember water requirements of succulent plants are highest in spring and summer when they are actively growing, and gradually reduce as the weather changes, reducing to a minimum in winter.
While sempervivum tectorum can grow well even without fertilizing, experts suggest feeding it once with a controlled-release fertilizer at the start of every season.
A liquid fertilizer, however, would need to be applied once a week, in diluted form.
Use a fertilizer with lower nitrogen concentrations on young plants and balanced fertilizer, at 1/4th strength, to feed the mature houseleek plants.
Soil & Transplanting
Homewort requires light and well-draining succulent soil mixture with a neutral pH for proper growth.
Transplantation of offsets should preferably be done in warm weather.
Before taking a young plant out, make sure the soil is completely dry.
Remove damaged, rotten, or dead roots and treat any wounds or cuts with a suitable fungicide before planting in the new pot or at the new site.
Do not water the plant for about a week after transplanting as it could cause root rot.
Grooming and Maintenance
Since St. Patrick’s cabbage is evergreen and hardy plant, it does not have much maintenance requirements apart from ensuring the proper drainage of the soil.
Waterlogged soil can damage or even kill the houseleek.
How To Propagate Houseleek
Common houseleek plant is called hen and chicks because of its natural growth habit.
The original or mother rosette (a hen) readily produces offsets (chicks) from horizontal stems, in all directions.
The offsets cluster around the mother rosette just like chicks gather around the mother hen.
The plant can easily be propagated by dividing these naturally produced offsets.
Sengreen also propagates from seeds and seedlings.
- Sprinkle the seeds on the top of the soil, preferably in a pot during the fall, and water lightly.
- Keep the soil moderately moist until the seeds germinate.
- When the seeds start to sprout, add some fine gravel around them; it works like mulch.
- Transfer the young plants to the ground in the spring.
Here are a few tips you should remember and follow for successful propagation of this plant:
- Do not plant roof foil too deeply in the soil and always spread the roots while replanting.
- Cover the plant up to the crown and compress the soil gently to ensure it is firmly set in the pot or ground.
- Water lightly and let the roots of new plants dry out completely between waterings.
Houseleek Pest or Diseases
A few varieties of houseleek plants can develop Endophyllum rust, a type of fungal disease. The plant can develop crown rot.
However, both these problems develop due to overwatering or poorly drained soil.
It is easily prevented by growing the plant in dry conditions.
It is deer resistant.
Sempervivum Tectorum Uses
While the devil’s beard grows slowly in height, it readily spreads to about 3’ feet horizontally, making it a good choice as a ground cover.
The plant is also grown in many areas for certain medicinal purposes and traditional beliefs.
They are considered alpine or rock garden plants, because of their hardiness and for being drought tolerant.
Tuck them into crevices and drape over walls for added privacy or beauty.
The juice from the plant is used as an astringent and the edible leaves are used for sore throats.