Echeveria and Sempervivum have many differences. There's exactly three things they have in common. One: They are both obviously gorgeous. Two: They all have a rosette shape. Three: They prefer and thrive in dry climates and soil.
Beyond that, these two popular succulents could not be more different.
Echeveria come from warmer, more temperate climates. Mexico, Central America and northwestern America are where all Echeveria originate from. The temperatures are warm year-round, the climate is dry and mostly desert-like regions.
Sempervivum originate from colder temperatures. They come from Iberia, Armenia, Balkan and Carpathian mountains. You will find them in the Alps, Morocco, Iran and the colder parts of the northeastern Sahara desert. These tend to be freezing cold temperatures and mostly dry regions.
Most Echeveria will prefer hardiness zones between 9-11. They can live indoors as well with proper lighting, little watering and neglect. If you live in an area that is freezing in the Fall and Winter, I recommend planting these in pots that can easily be moved inside to keep them safe.
All Sempervivums can handle hardiness zones 4-10. They thrive outdoors in freezing cold but dry environments. Freezing temperatures and dry conditions can really bring out the color in these.
To check your hardiness zone, click here.
Shape, Color, Foliage
The Echeveria will vary in shape and color. Reference the image on the left. They come in a variety of colors, and depending on sunlight, watering and temperature, can change their foliage due to stress.
They will also have a white, powdery coating on their leaves, called Farina. This is a protective layer they naturally develop help it keep its moisture in the leaves, and prevent it from being scorched by the sun.
The leaves and stems are plump because they store their water those areas to sustain itself.
Sempervivums usually have a serrated margins on their leaves. The color will usually be green, but with stress, they can turn a red or purple color in the right conditions.
The leaves will lack Farina mostly because they don't need in in their natural habitat.
The leaves tend to be thin, pointed, and much more dense because of the thinness of the leaves.
Echeveria tend to produce offsets at the bottom of the plant near the base of the stem. Check your Echeveria out now, you may have 1-3 babies you didn't even know about growing there.
A Sempervivum offset will be positioned around the mother plant. And she will usually give birth to 2-6 plants at the same time. These are hooked up to a stem that feeds it the necessary nutrients, almost like an umbilical cord.
Once either plant is big enough, feel free to remove it and plant it in its own pot.
Blooms on the Echeveria (left image above) will usually take place in the Spring and Summer, when they are in their most active growing phase.
They will typically be a long stem that produces many colorful flowers and may occur more than once during this time.
A Sempervivum bloom (right image above) will happen only once. It literally goes out with a bang. It shoots out this big, marvelous bloom from the center of the plant, and then the mother plant will die off. Before it does, it will give you many offsets to play with. It's always bittersweet to see a Sempervivum bloom.
The Echeveria can be propagated by leaf, stem, offset and cutting. One plant with 12 leaves can potentially get you 12 new plants if propagated properly and carefully.
If you behead an Echeveria, 2-3 new plants can come grow from the cut stem.
Sempervivums cannot be propagated by leaf or stem. Offsets taken from the plant and repotted is the only way to propagate these. Or you can do it the old fashioned way and get seeds, but that just seems so unnecessary.