For measurements, a plant that is 6" in size refers to a plant growing in a nursery pot that is 6" in diameter pot size, regardless of the size of the plant. A general rule of thumb is to pick a pot that is a little bigger than the plant. For example, 6" plant should fit into a 7" pot, a 3.5" plant should fit into a 5" pot, etc. Another tip, we recommend choosing a pot with drainage holes. This is important because if the water does not drain properly it will cause the roots to rot and damage your plant. Refer to the picture below.