Why people love it
Pencil cactus is pure sculpture. Its smooth, finger-thin stems branch again and again into a bright green, bushy shape. The popular ‘Firesticks’ form turns orange and red at the tips in strong sun. It grows fast in good light and needs very little water.
Handle with care
Pencil cactus isn’t a cactus. It’s a euphorbia, and like other euphorbias it bleeds a white, milky sap when a stem is cut or snapped.
- The sap irritates skin and eyes. Wear gloves and eye protection when you prune or take cuttings, and wash your hands afterwards.
- Keep it away from pets and children who might chew it.
- Rinse sap off tools before it dries.
Care in a nutshell
- Full sun. In dim light, the stems stretch and flop.
- Water sparingly. It’s very drought tolerant. Too much water is the usual way to lose one.
- Prune to keep it in shape. Cut stems where they branch, wearing gloves.
Taking cuttings
Cut a stem tip about 4–6 in (10–15 cm) long, wearing gloves. Rinse the cut end under water to stop the sap flowing, then let it dry for several days until it forms a callus. Plant it in dry cactus mix and wait a week before watering.
Watch out for
- Shriveled, soft stems at the base usually mean root rot. Take cuttings from healthy tips and start again.
- Pale, floppy growth means it needs more sun.
Fun fact: The plant has tiny leaves on new growth, but they drop off quickly. The green stems do almost all of the plant’s photosynthesis.
