How to Care for a Pencil Cactus
Light: Pencil Cactus love bright and direct sunlight. You can place your cactus outside as long as it's above 18 degrees. An east facing, or south east facing window will be just great.
Water: A Pencil Cactus is drought resistant, and only needs water once every 2 to 3 weeks. They prefer to dry out between waterings. Your cactus should feel very light in weight, and then you know it's time to water again.
Soil: Well-draining potting mix will let a Pencil Cactus thrive.
Humidity: The average humidity in a house is great