Yes, hens and chicks winter survival is one of their best traits as garden plants. These tough rosettes shrug off temps as low as -30°F (-34°C) when planted in the ground. They are some of the most cold hardy succulents you can grow.
I have grown them through brutal Wisconsin winters for eight years running now. After a snow melt in March, the rosettes look closed tight and a bit purple from cold stress. By April, they plump back up and start pushing fresh chicks like nothing happened to them.
The science behind this freeze resistance comes from their fat leaves. Each cell holds a thick sugary sap that acts like natural antifreeze inside the plant. This sap drops the freezing point of the water in their tissues so ice crystals do not form and burst the cells.
Sempervivum winter care starts in fall with one simple step. Stop watering by mid October so the rosettes go into the cold months on the dry side. Wet roots and freezing temps together cause more dead plants than cold alone ever does.
NC State Extension lists Sempervivum tectorum as hardy down to USDA Zone 3a. That means it can take lows of -35°C (-31°F). No cover is needed in most cases. Other named types hold up just as well in cold zones.
Overwintering hens and chicks in pots takes more thought than ground plants. Roots in a container freeze faster and harder than roots in the open ground. Move pots against a south wall or sink them into a garden bed for the winter to buffer the cold.
Skip the heavy mulch over crowns no matter how cold your zone gets in winter. Wet leaves and bark trap moisture against the rosette and cause crown rot by spring thaw. A thin layer of pea gravel works much better as a winter blanket.
Snow makes the best winter cover these plants could ask for from nature. A blanket of 6 inches (15 cm) of snow holds the soil at a steady 28°F (-2°C) even when the air drops much colder above the surface. Leave snow where it falls on your beds.
USDA Zone 3 succulents like these can handle just about anything winter throws at them across the country. Just give them sharp drainage, keep them dry in fall, and skip the heavy cover. Your colony will push fresh growth at the first sign of spring sun.
In my experience, the rosettes that fail in winter almost always die from wet soil and not from cold itself. When I tested side-by-side beds one harsh year, the ones with extra gravel mulch came through fine. The ones in plain topsoil rotted at the crowns.
You can tell your plants made it through winter by checking the inner leaves in March. If the center stays firm and tight, you have a live rosette ready to grow. If the core feels mushy or pulls apart in your hand, you lost that plant to wet roots.
Container plants need one more trick that ground plants do not. Wrap pots in bubble wrap or burlap when temps drop below 10°F (-12°C) to slow the freeze. This buys your roots time to adjust without sudden ice damage on the inside.
Read the full article: Hen and Chicks Plant: Care Guide
