How long do I have to keep watering my bamboo?

On May 4th I received an email from a customer in Orlando who bought bamboo from us over a year ago: 

My neighbor asked if my bamboo will always need to be watered. (The sprinkler is on as I write this.) I told him that when the rainy season has arrived, then I needn’t water, but that during the dry season – even after the bamboo is established – I’ll need to water twice a day. Am I correct?

By the way, the bamboo is finally becoming truly a privacy wall, though, surprisingly, I’ve not yet had any new canes this year. I did fertilize two weeks ago.

My response:

New canes will be appearing soon.  May - November is the time to see above-ground growth.  About the watering, after a year you can stop watering your plants entirely if you wish but they will grow bigger faster if given regular water as you've been doing.  Once the bamboos fill in to a point where you are happy with their look, you can cut back severely on irrigating.  We have mature clumps of bamboo all around our property that we never water and they are doing just fine. 

In this picture our son Toby (how little he was in 2004!) is standing next to a 10-year-old stand of Bambusa multiplex silverstripe (Green Hedge Clumping Bamboo).  We gave the hedge regular water for the first couple years but since then it hasn't been irrigated at all.