How to Grow and Care for Cobweb Succulent

The Cobweb Succulent, or Sempervivum arachnoideum, is a distinctive alpine plant known for its captivating appearance. It forms tight, low-growing rosettes of fleshy leaves that can be green or tinged with red. Its unique feature is the fine, white filaments stretching between leaf tips, resembling a spiderweb. This natural webbing helps protect the plant from intense sun and reduces water loss. As a “Hen and Chicks” plant, the main rosette (the “hen”) produces numerous smaller plants (“chicks”) around its base.

Cobweb Succulent Care

Light

Sempervivum arachnoideum requires ample sunlight to maintain its compact form and webbing. Outdoors, provide at least six hours of direct sunlight per day, though some afternoon shade can prevent scorching in hot climates. When growing indoors, place it near a south or west-facing window to provide the necessary bright light. Without enough light, the rosettes may stretch and lose their web-like covering.

Soil

Native to mountainous regions, the Cobweb Succulent demands a gritty, well-draining soil mix to prevent water from accumulating around its roots. A suitable medium can be made by combining equal parts potting soil, coarse sand, and perlite. Alternatively, commercially available cactus and succulent mixes are formulated to provide the necessary drainage. Containers must have drainage holes to allow excess water to escape, and for ground-planted specimens, amending the soil with horticultural grit improves drainage.

Water

Cobweb Succulents are drought-tolerant, so overwatering is a common mistake. The best watering technique is the “soak and dry” method, where the soil is drenched and then allowed to dry out completely before the next watering. During the spring and summer growing season, water once every one to two weeks. Reduce watering significantly in the winter when the plant is dormant. Always water the soil at the base of the plant to prevent moisture from getting trapped in the webs.

Temperature and Hardiness

Sempervivum arachnoideum is a cold-hardy succulent suited for USDA zones 5 through 8, withstanding temperatures as low as -20°F (-29°C). This resilience makes it a good choice for outdoor rock gardens, containers, or stone walls where it can be left year-round. While frost-tolerant, well-draining soil is necessary to prevent water from freezing around the roots. The plant tolerates heat but benefits from protection during extreme heatwaves to avoid sun damage.

Propagating Cobweb Succulents

The most common propagation method is separating the offsets, or “chicks,” that form around the base of the main plant. This straightforward process has a high success rate, allowing gardeners to easily expand their collection. Each small rosette is a genetic clone of the parent plant.

The ideal time to propagate is during the spring and early summer when the plant is in its active growth phase. Look for offsets that have reached a reasonable size, at least a couple of centimeters in diameter, and may have started to form their own small roots. Waiting until the chicks are established gives them a better chance of surviving on their own.

Use a sharp, sterile knife or scissors to carefully cut the stolon connecting the chick to the main plant, including some of the chick’s roots if possible. After separating the offset, it is beneficial to let it sit in a dry, shaded area for a day or two. This allows the cut end to form a callus, which helps prevent rot when it is planted.

Once callused, the offset is ready for planting in a small pot with well-draining succulent mix. Make a small hole in the soil, place the offset’s base into it, and gently firm the soil around it for support. Water sparingly to settle the soil, then wait for it to dry out completely before watering again. The new plant should establish its root system and begin to grow within a few weeks.

Common Issues and Solutions

Root rot is a frequent problem caused by overwatering or soil that does not drain properly. The first signs include lower leaves that appear translucent, discolored, or feel mushy. To resolve this, remove the plant from its pot, trim away rotting leaves and roots, and let it dry for a few days before replanting in fresh, dry, well-draining soil.

Insufficient light causes etiolation, where the succulent stretches and loses its compact rosette shape. The stems elongate and leaves become spaced out as the plant reaches for light, which weakens it. To fix this, gradually move the plant to a location with more direct sunlight, like a south-facing window or a sunnier garden spot.

Pests like mealybugs can occasionally be an issue. These small, white insects feed on the plant’s sap, hiding in the leaves and webs, which can cause stunted growth and distorted leaves. For minor issues, remove individual mealybugs with a cotton swab dipped in rubbing alcohol. Larger infestations may require treatment with an insecticidal soap.

Understanding Cobweb Succulent Flowers

The flowering of a Cobweb Succulent marks the final stage of an individual rosette’s life. As a monocarpic plant, a rosette will die after it blooms and produces seeds. This is a natural part of its life cycle, not a sign of poor health, and occurs after a rosette matures over several years.

Signs of impending flowering include the center leaves tightening and the rosette elongating into a tall flower stalk. In summer, this stalk produces a cluster of star-shaped, pinkish-red flowers. While the flowering “hen” will die, this is not the end of the plant colony.

Before a mother rosette flowers, it produces many offsets (“chicks”) around its base. These chicks are unaffected by the flowering process and will continue to grow and mature. The death of the flowering rosette leaves a gap that is quickly filled by the surrounding colony, ensuring the plant continues to thrive.