Blue Chalksticks (Curio repens)

Overview

Blue chalksticks is a low, spreading succulent whose plump, finger-shaped leaves are coated a striking powdery silver-blue - like sticks of blue chalk. Tough, drought-proof and happy to spill from a pot or carpet a sunny bed, it is one of the easiest ways to add cool blue to a succulent collection.

Origin & Natural Habitat

Curio repens (long known as Senecio serpens) comes from the winter-rainfall Cape region of South Africa, creeping over rocky slopes. Its waxy blue coating is sunscreen against intense light.

Appearance

Upright, finger-like, blue-grey leaves with a chalky bloom, packed along creeping stems that root as they spread. Small brush-like white flowers appear on stalks in summer. The blue intensifies in strong sun.

Why People Love It - Qualities & Benefits

People love the true silver-blue colour - a perfect contrast to green and red succulents - and its easy, spreading habit. It fills pots, spills nicely and shrugs off drought and neglect.

Care

Light

Full sun for the best blue and a compact carpet - a very sunny windowsill or outdoors in warm weather. In shade it greens and sprawls loosely.

Watering

Soak when the soil is fully dry, then wait; the fleshy fingers store plenty. Keep drier in winter. It far prefers drought to damp and rots in soggy soil.

Soil & Potting

A gritty, free-draining succulent mix in a pot with drainage - or a lean, sandy spot outdoors in mild climates.

Humidity & Temperature

Dry, airy conditions suit it; ordinary room air is fine. It tolerates brief light frost in the ground but is safest kept above about 5°C in a pot.

Feeding

A dilute succulent feed once or twice in the growing season is ample.

Repotting

Repot or trim every year or two as it spreads; the creeping stems make it easy to reshape. Handle by the stems to preserve the chalky bloom on the leaves.

Propagation

Very easy from stem cuttings: snip a length, callus a few days, and lay or plant it in gritty mix - it roots along the stem. Clumps also divide simply.

Common Problems & Pests

Overwatering rot is the main risk. Handling rubs the blue bloom off (cosmetic). Mealybugs and aphids occasionally visit. Leggy green growth means too little sun.

Toxicity & Safety

Blue chalksticks is considered mildly toxic if eaten and its sap can irritate skin - as with other senecio relatives, keep it away from nibbling pets and children and wash hands after pruning.

Pros & Cons

Pros: striking silver-blue colour, tough and drought-proof, spreads and propagates easily. Cons: mildly toxic if eaten, bloom rubs off with handling, needs full sun for colour.

Best Suited For

For anyone building a colour-contrast succulent display - the reliable blue that ties a collection together, best kept away from curious pets.

FAQ

Why has my plant gone green? Not enough sun - full light brings back the chalk-blue coating on new growth.

Is it safe for pets? Treat it as mildly toxic - keep it out of reach and wash hands after handling the sap.