How I intend to control my lemon trees' growth by using bonsai methods...

By cutting off  the bottom 2/3 of the roots...

and careful pruning....

a bonsai tree is born!...and thats exactly what im going to do to my lemon trees! (When they reach a height of 3.5 - 4 feet, that is). I am still in the stages of learning this my self so it will be a neat experiment, but to tell you the truth I'm a little nervous about it. It could go terribly wrong and my tree might not recover from the stress of the pruning and root cutting, but its something I have to do if I want a manageable ornamental tree and not a 30 foot monster in my apt. So its all or nothing here!