Pilosocereus tillianus

Most cactus, like this one, are from the deserts of the world and as such like to go totally bone dry between waterings, making them very low-maintenance. If you see your cactus begin to shrivel or lose firmness, your cactus is likely totally dry and should be watered. To get good healthy growth your plant does not want to sit around totally dried out during its growing season. Once it is dry, water it.

This cactus comes from an area with seasonal rainfall and is actively growing during that warmer weather, when it is forgiving of overwatering errors. During winter dormancy it should be kept extra dry and won't tolerate overwatering.

Remember that if kept in a small pot your plant will want more frequent watering.