Pencil cactus
Euphorbia tirucalli
Pencil-thin green branches carry tiny leaves that soon drop; the sap is milky.
Find its rhythm
Light
Strong light; acclimate gradually to direct sun
Water
Allow the potting mix to dry before watering thoroughly. Do not leave water in the saucer. Start with a soil check every 14 days and adjust for your conditions.
Care through the seasons
Soil & drainage
Use a gritty, freely draining cactus or succulent mix.
Climate
Provide airflow; check species hardiness before leaving outside in cold weather.
Seasonal care
Dormancy varies by species. Reduce watering when growth stops; avoid a fixed year-round schedule.
Feeding
Use a light feed during active growth only, according to the label.
Pruning
Remove dead material carefully. Protect skin from spines and irritating sap.
Propagation
Stem cuttings
Hardiness
11a, 11b, 12a, 12b
Watch for
Rot in wet soil · Stretching in low light · Sun scorch after a sudden move
Care-group starting guidance; adapt to your cultivar and local climate.
Pet & child safety
Toxic to cats and dogs (ASPCA)
Signs in cats and dogs (ASPCA): Irritating to the mouth and stomach, sometimes causing vomiting, but generally over-rated in toxicity.
Moderately toxic to children (California Poison Control)
Moderate toxicity: eating it is expected to cause nausea and vomiting, but it is not expected to be life-threatening.
Skin irritant: touching the sap or leaves can cause redness, itching, a rash or blisters.
Keep plants out of reach of children and pets. Never eat a plant based on an app.
If any is eaten: Call your local poison control centre or vet. In the US: Poison Control 1-800-222-1222; ASPCA Animal Poison Control (888) 426-4435 (a fee may apply).
Sources checked 10 Nov 2026. Lists change, so check the source before relying on it.