Pencil Cactus
Euphorbia tirucalli
A nearly leafless succulent shrub whose mass of slender, pencil-thick green branches gives it a coral-like silhouette. It is striking and easy to grow.
- Light
- Full sun to bright light
- Water
- Sparingly; let dry fully
- Difficulty
- Easy
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Overview
Despite the name, Pencil Cactus is not a cactus but a succulent Euphorbia from Africa. It forms a tangle of smooth, cylindrical, pencil-width stems and carries almost no visible leaves, performing photosynthesis through its green branches.
Popular cultivars such as 'Sticks on Fire' flush vivid red, orange, and yellow at the stem tips in bright light. It is famously tough and architectural. Wear gloves and eye protection when pruning, as the stems exude a milky latex.
How to identify it
Recognize it by its dense, branching mass of thin, smooth, green cylindrical stems with no spines.
- Stems: pencil-thick, smooth, bright green, freely branching into a coral-like form
- Leaves: tiny and short-lived, usually absent on mature plants
- Color: 'Firestick' types turn fiery red-orange in sun and cool weather
- Sap: copious milky white latex from any break
- Size: a few feet in a pot, up to 20-30 ft as a tree in the wild
Care & growing
Light: Full sun to very bright indirect light; more light intensifies stem color.
Water: Water sparingly and let soil dry completely; it is extremely drought tolerant and rots if kept wet.
Soil: Gritty, fast-draining cactus mix.
Temperature: Loves warmth (65-90F); protect from frost.
Feeding: Light feeding once or twice in the growing season is plenty.
Propagation: Stem cuttings root easily; let the cut callus for several days first. Always wear gloves and eye protection when cutting.
Habitat & origin
Native to semi-arid regions of Africa and the Indian subcontinent, where it grows as a large shrub or small tree in dry, open landscapes.
It is now cultivated worldwide as a sculptural ornamental and hedge plant in frost-free climates, and as a container houseplant in cooler regions.
Frequently asked questions
Why are the stems turning red?
In firestick varieties, bright sun and cooler temperatures trigger the vivid red-orange coloring. More light equals more color; shade returns them to green.
How big will it get indoors?
In a container it usually stays 2-6 ft and can be pruned to size. In tropical ground it becomes a large tree.
How often do I water it?
Rarely. Let the soil dry out fully, then water lightly, roughly every 2-3 weeks in summer and almost never in winter.
Why does it ooze a milky liquid when cut?
The stems contain a white latex sap that flows from any break. Wear gloves and eye protection when pruning and keep it off skin and face.
Pencil Cactus guides
In-depth guides for identifying, growing, and caring for Pencil Cactus.
