The lighting requirements for succulents will differ depending on whether they are indoors or outdoors. Make sure you have adequate lighting, and only water your plant after the soil has dried to the top. The soil may dry too quickly in summer, leaving your plant without enough water. The unique plant can grow in clumps up to 4 inches high and 12 inches wide. They can do well in a window sill on a south or west-facing window. We think a modern white window sill planting container like this will look stunning with the Bishop’s Cap cactus.