Firestick Plant
Euphorbia tirucalli
Firestick Plant, also called Pencil Cactus, grows dense pencil-thin stems instead of typical leaves. Stems stay green in lower light and shift toward yellow, orange, and red in strong sun. Handle with care: the milky sap is highly irritating.
Light
Full Sun
Water
Low
Difficulty
Easy
Humidity
Low
Pet Warning
Highly toxic to pets and humans. The milky sap can cause severe skin irritation, temporary blindness if it contacts the eyes, and internal distress if ingested.
Care Notes
Light
Strong light keeps the red and orange color. Aim for at least 6 hours of direct sun. In low light, stems stay green and may stretch.
Water
Use soak-and-dry watering. Soak until water drains out, then wait until the soil is fully dry. In winter, water about once every 4 to 6 weeks.
Soil
Plant in a sandy or gritty cactus mix with extra perlite, pumice, or coarse sand if needed. A container with ample drainage holes is required.
Humidity & Temperature
Low humidity is fine. Keep temperatures between 65°F and 85°F (18°C-29°C), and bring the plant indoors below 50°F (10°C). Always wear gloves and eye protection when pruning; wash off any sap with soap and water right away.
Common Issues
Soft stems and root rot follow overwatering. Green, stretched growth means the plant needs more sun.
In-Depth Care & Growth
Feeding & Soil
Fertilizer
Balanced liquid succulent fertilizer (10-10-10)
Soil
Well-draining, sandy or gritty cactus/succulent mix
Physical Attributes
Mature Size
4-8 feet indoors, up to 30 feet in optimal outdoor conditions
Growth Rate
Fast
Propagation
Stem cuttings (allow cuttings to callous for several days before planting; handle with gloves)
Common Varieties
Sticks on Fire
Leafless pencil-thin stems that shift from a lime-green base to golden yellow and coral-red tips.
Rosea
Upright pencil-thin stems that move from bright green into yellow, orange, and rose-pink.
Pencil Cactus
This form has slender cylindrical stems without typical leaves, green at the base and coral-orange to red at the tips in strong light.