Chris,
This is a pretty aggressive weed IMO/IME...
It gets thick very quickly and provides numerous 'tops' fairly easily.....w/o any mowing...
I can't imagine how many Tom has after a major mowing....
I will be doing my first one soon to provide shoots to plant the entire tank as I want and expect to have plenty left over...
And I am just an amatuer grower compared to Tom and others...once I provided good conditions they have taken off quickly and spread rapidly...
It is just about my favorite plant right about now
That shot above would provide literally hundreds of great tops and cuttings of all sizes.....