Patris-
Why would you want to cut it back? There are a few shrub bamboo that benefit from shearing in the spring and, sometimes when you dig a big field division, topping the culms may help balance out the rhizome/leaf ratio, but I wouldn't do it to a conventional bamboo of the size you describe which is already stabilized in a pot. If you're trying to force more growth, the best thing would be to get it in the ground and water, mulch, and fertilize it (since it's fall, I'd use 0-10-10 to promote rhizome growth).

Thanks kudzu, especially for the tip on fall fertilizer.

I did not say I wanted to cut this one back.
I was just asking for advice as bamboo is new for me.
There are a lot of plants when taken out of the pot seem to do better with a little tirm. Since I am so new thought I would ask before I decided on her permanant location.

Thanks

Patris-
One other thing I should have made clear to help with my explanation... Maybe you know this, but each culm reaches its maximum height in the couple of months after it sends up shoots. If you were to cut off a culm, it would never relengthen. It wouldn't hurt the plant, but you'd have some stubby, short culms and the plant would only get tall again when new shoots came up next year.

Thank you much!

I have two golden goddess bamboos that are drying out. I need to know if I should trim the dried out part or just keep watering them. There is still very littl green leafs but the stocks are still green(most of them). Please help I really like the way there look.

cindy-
Keep watering it properly and don't be so hasty to trim it back. Give it until the middle of this summer to see what comes back, and then trim back any culms that appear dead then.