Michelle,
This plant is not running in the style of bamboo, but you definitely need to allow enough space for its mature size, and if this is going into your backyard, I am sure you are trying to jam it on in where you don't have quite this much space. They can easily get 6 foot tall by across if allowed to grow unrestricted. I might suggest planting it out into a 30 gallon or so sized bottomless container in the ground might be a better solution, and dig it up and move it when it outgrows the spot!