Cobweb Houseleek Seeds – Sempervivum arachnoideum, 50 Seeds

Delicate Cobweb Texture in a Succulent Rosette

Cobweb Houseleek (Sempervivum arachnoideum) brings distinctive detail to rock gardens and succulent containers. Densely arranged rosettes of fleshy, reddish-green leaves are linked at their tips by fine white hairs, creating the cobweb-like appearance that gives this plant its common name.

Grow these small succulents from seed and enjoy their changing rosette shapes at close range in a trough, pot, or rocky planting pocket. As plants mature, smaller offsets can form around the parent rosette, gradually building a clustered display.

What You Receive

One packet of 50 seeds for planting. This is not a live plant, rooted offset, or established succulent. Plants grown from seed need time to develop their mature appearance.

Plant Highlights

• Botanical name: Sempervivum arachnoideum.
• Common names: Cobweb houseleek and hens and chicks.
• Life cycle: Perennial succulent.
• Foliage: Fleshy, reddish-green rosettes with fine white, cobweb-like hairs.
• Approximate foliage height: 2–4 inches under suitable conditions.
• Flowers: Mature rosettes may produce rose-red flowers in summer.
• Growth rate: Slow, particularly while seedlings establish.
• Light: Full sun to partial shade, with some afternoon shade helpful in hot southern conditions.
• Soil: Well-drained soil; the supplied growing information lists a pH range of 5.5–7.0.

Important: Tiny Seeds

These seeds are extremely small and can be difficult to see. Open the packet indoors, away from wind or drafts, over a clean sheet of white paper. Check the packet folds before discarding it. Sow sparingly and water gently so the seeds are not washed away.

Starting from Seed

• Prepare pots: Use a seed tray or small pots with drainage holes and a fine, well-draining seed-starting mix.
• Sow shallowly: Press the seeds gently onto the surface. Cover only very lightly with fine peat moss or seed-starting mix; light is needed for germination.
• Temperature: Maintain approximately 70–75°F.
• Moisture: Keep the surface slightly moist, not saturated. Mist gently or water carefully without disturbing the seeds.
• Germination: The supplied directions give approximately 7–21 days under suitable conditions, though timing can vary.
• If germination is delayed: The supplied directions suggest a brief 1–2 week refrigerator treatment, followed by a return to 70–75°F. Keep the mix lightly moist and do not freeze it.
• After sprouting: Provide good light and airflow, and let seedlings develop before handling or transplanting.

Growing in Containers

A trough or small succulent planter lets you appreciate the fine cobweb texture up close. Choose drainage over decorative containers that trap water.

• Use drainage holes: Excess water must be able to leave the pot freely.
• Choose a gritty mix: Use a well-draining potting mix suitable for succulents.
• Provide suitable light: Place in sun to partial shade and introduce young plants to stronger sunlight gradually.
• Adjust watering as plants mature: Keep seedlings lightly moist while establishing. For established plants, allow the mix to dry between waterings and avoid standing water in saucers.
• Leave growing room: Allow space around the parent rosettes for offsets to develop.
• Avoid prolonged wetness: Keep drainage clear and protect pots from conditions that leave the mix continually saturated.

Rock Garden and Seasonal Care

Choose a freely draining planting pocket or raised position where water does not collect. A mature rosette dies after flowering, while surrounding offsets can continue growing. Remove dead rosettes carefully without disturbing neighboring plants.

Winter performance depends on local conditions and drainage. Avoid treating a broad zone range as a guarantee for every growing situation.