why can't I append to div in ember?

I have a <div id="container"></div> in my examples.hbs. In my controller I have an init function:

init: function(){ $('#container').append("test 123"); }

But this doesn't append anything. However if my div container is in my index.html I do see 'test123' being appended. That makes me believe that the init function is being called before the template has rendered.

So I guess my question is what is the proper way to append things on initialization?

Note: I am using Three.js which creates a webGLRenderer, and I am just appending this renderer (ie canvas) to the container.