About Sempervivum
Sempervivum is a winter-hardy, evergreen succulent forming compact rosettes in a vibrant color mix. Known for its drought tolerance and striking architectural form, it’s ideal for rock gardens, green roofs, mixed succulent containers, and even indoor decorative planting. Non-branching flower spikes attract bees when in bloom. Sempervivum is hardy in zones 3a through 9b.
When to Plant Sempervivum Seeds
We recommend that gardeners begin their sempervivum seeds indoors four to six weeks before your last expected frost. This ensures seedlings are sturdy and ready to plant outside once weather warms.
Another option is to directly seed in spring once the last spring frosts have passed and the soil temperature has warmed. Make sure nighttime temperatures remain above 50°F.
Gardeners in zones 7 through 9 who experience mild winters can sow seeds in autumn. Young plants must be well-rooted before any frost.
Where to Plant Sempervivum Seeds
When beginning your seeds indoors, use a well-draining cactus/succulent mix. Place your flat before a bright south-facing window or under grow lights.
If directly sowing, choose a full sun location for vibrant color and compact growth. When light is insufficient, sempervivum tends to grow leggy. Make sure your location has well-draining sandy or gritty soil.
Ultimately, their ‘forever home’ should be in rock gardens, gravel beds, alpine troughs, dry stone walls, small area ground cover, or shallow containers.
How to Plant Sempervivum Seeds
Sempervivum seeds are miniscule; open packaging carefully. Sow seeds in seed trays or small pots filled with a well-draining cactus/succulent mix. Lightly cover with a thin layer of fine grit, vermiculite, or peat moss. Sempervivum seeds need light to germinate, so do not cover with too thick a layer. Read more about light requirements here.
Lightly spray seeds with water so as not to wash them away. Keep your young starts at 65°F to 70°F and evenly moist by not soggy. Provide bright light immediately after sowing as this will help prevent leggy seedlings. Expect germination in two to four weeks.
How to Care for Sempervivum
As long as you are growing your sempervivum in well-draining soil, water your plants once a week from spring through summer. When cooler temperatures arrive in fall and winter, restrict their water to only once a month. Giving too much water may cause the roots to rot.
Transplanting your young sempervivum plants from the growing tray to a new location is fairly easy. Use a spoon to come up and under the rosette, taking care not to cut through the roots. Just scoop down a few inches below the soil line and lift the rosette up. You can now transplant it in its new home.