Q.how tall do balloon flowers get
Trying to plant from tallest to shortest.

The answer to your question really hinges on the variety you have - different varieties differ in plant size. According to Cornell University, the height of balloon flowers is 2.5 to 3.5 feet with some dwarf varieties reaching just 6 inches tall.
For more information on balloon flowers, please visit the following link:
https://www.gardeningknowhow.com/ornamental/flowers/balloon-flower/growing-balloon-flowers.htm