When many people think bamboo they panic and start worrying about uncontrolable grassy rooty clumps popping up all over the village causing widespread panic on the scale of "Day of the Tryphids" and the possibilty of hosing them down with salt water to save the planet. There is a bit truth to that sort of problem if you plant those awful sassa varieties. They ought to remame them as weeds so as not to put you off the large clump forming Phyllostachys bamboo. These are totally different and are excellent for screening and or specimen planting. Interesting stem colours from yellows to black.They make a graceful screen whilst adding movement to the garden. You will need some room as they make large bushy clumps and a little like their awful aforementioned cousins can run a little off piste. If you are tight for room it can become embarrassing if they erupt through next doors decking. Don't panic Captain Mainwaring, they only run fairly shallow and soon give up to a spade. Then you can perpetuate the joy by giving a small clump to aunt Fanny. As far as height is concerned they grow in relation to the soil condition. In perfect deep humous rich moist soil they will grow much taller than in heavy clay,by almost double with out looking any less attractive at the smaller height. If you are paranoid about them escaping from the position you want them in or your garden is very small, you can plant them in a plastic dustbin. Black bamboo like it wetter than the other colours and you should keep that in mind in March when planting new bamboos as they can dry out very fast in the wind especially the black ones. There is something deeply satisfying in April when you see the new spears errupting through the soil and rearing up at over a foot a week.