Pencil Cactus - toxic

Light - Full Sun. At least six hours of sunlight on most days. However, it can tolerate a bit of shade and might even appreciate some protection from the hot afternoon sun. Indoors, grow it by your brightest window. It can also tolerate bright, indirect light.

Water - This plant is highly tolerant to drought, and too much water can rot its roots. Water every two to three weeks in the spring and summer. Reduce watering to monthly in the fall and winter.

Mature Size - 20–30 ft. tall, 6–10 ft. wide (outdoors), up to 6 ft. tall, 1–3 ft. wide (indoors).