Curio hallianus

A blue-leaved creeper from Great Karoo rock fissures

Curio hallianus is a trailing succulent in the daisy family, native to the Cape Provinces of South Africa. Its stems spread close to the ground and carry fleshy blue-green leaves in a mat-forming arrangement.

Wild plants grow in rock fissures around Prince Albert and across the Great Karoo. The landscape is dry and stony, with strong sun, irregular rain and cooler weather during parts of the year.

Crevices offer pockets of soil and some shelter from the widest temperature swings. The creeping stems follow these narrow spaces, while succulent leaves hold moisture between rainfall events.

Light, drying and root care

Sunlight for blue-grey trailing growth

Give Curio hallianus the brightest indoor position available, directly at a south or west window or under a strong grow light. Let Curio hallianus adjust before it receives long periods of sun through glass.

Drying the pot beneath blue-grey trails

Water only after the mix has dried through most of its depth. Pour slowly until all of the substrate is wet, then let the pot drain freely.

Watering, temperature and root care

A bright, cool, frost-free winter position is suitable when the intervals between waterings are lengthened.

Lean nutrition for firm blue-grey stems

Curio hallianus needs little fertiliser. During firm new growth, use a complete succulent feed at a low dose.

What the blue beans of Curio hallianus are showing

The blue-grey beans sit mostly along one side of each stem

One-sided leaf placement is characteristic of this trailing species, not leaf loss by itself. Look for bare scars where beans have detached or for increasing gaps in new growth. Give brighter light gradually if new stems are thin and sparsely furnished, and handle the easily marked coating as little as possible.

The blue beans become wrinkled

Firm wrinkling above dry mix usually means stored water is depleted. Wrinkles above damp compost can indicate failed roots or a rotted stem base. Inspect before watering: sound stems are firm and pale, while damaged ones are brown, translucent or hollow. Rehydrate healthy roots or propagate clean tips above the damage.

New stems are green, thin and widely spaced

Insufficient light spaces the narrow leaves farther apart and weakens their blue-grey colour. Move the plant gradually to stronger light and rotate it so the top of the pot is illuminated. Once firm compact growth resumes, root healthy tips to replace stretched sections; existing gaps will remain.

The trailing base turns brown and soft

This is consistent with stem rot, often beginning where crowded stems meet persistently wet mix. Lift the strands, remove all mushy material and cut back to firm tissue. Let clean succulent cuttings callus before rooting them in a fast-draining mix. Act before the soft section travels into apparently healthy blue beans.

Keep Curio hallianus away from children and pets

• Keep this plant away from children, cats and dogs.
• Its effects after chewing or swallowing are unclear, and plant material can still cause an upset stomach.
• Contact a veterinarian or medical professional if symptoms develop or do not settle.

Where does the name Curio hallianus come from?

Curio is linked to the Latin curiosus, meaning curious, in reference to the group's unusual forms. The epithet hallianus honours the British-born South African botanist and succulent specialist Harry Hall.

Paul V. Heath established the genus Curio in 1997 in Calyx, volume 5, page 136.

Gordon Douglas Rowley first described it as Senecio hallianus in 1958 in National Cactus and Succulent Journal, volume 13, page 33. Paul V. Heath later placed it in Curio as Curio hallianus in 1999 in Calyx, volume 6, page 54.