Pencil Cactus
Euphorbia tirucalli
Also known as: Pencil Cactus, Firestick Plant, Milk Bush
Euphorbiaceae
If your pet has eaten this plant, call ASPCA Poison Control: (888) 426-4435 — available 24/7.
Last reviewed: June 2026 · Source: ASPCA Animal Poison Control
Striking succulent with pencil-thin green stems. Turns orange and red in cool weather. Sap is caustic.
Toxicity
Source: ASPCA Animal Poison Control Center. Always consult a veterinarian if your pet ingests any plant.
Care Guide
Pot Size
Frequently Asked Questions
Is Pencil Cactus toxic to cats?↓
Yes, Pencil Cactus (Euphorbia tirucalli) is toxic to cats. If your cat ingests any part of this plant, contact your veterinarian or the ASPCA Animal Poison Control Center (888-426-4435) immediately.
Is Pencil Cactus toxic to dogs?↓
Yes, Pencil Cactus is toxic to dogs. Symptoms may include vomiting, drooling, or lethargy. Contact your vet immediately if your dog chews or eats this plant.
How often should I water Pencil Cactus?↓
Water Pencil Cactus every 14–21 days. Allow the soil to dry out completely between waterings — this plant is drought-tolerant and prone to root rot if overwatered.
How much light does Pencil Cactus need?↓
Pencil Cactus thrives in direct sunlight, ideally a south- or west-facing window. It is forgiving and adapts to a range of light conditions.
What size pot does Pencil Cactus need?↓
Use a pot between 6″ and 12″ in diameter. When repotting, choose a pot only 1–2″ larger than the current one — too much space retains excess moisture and can lead to root rot.