I received an addendum to the herbicide treatment. Garlon 4 (and
RoundUp) can be mixed with water, also. Adding a little detergent to
the mix would allow for the herbicide to better adhere to the slick
bamboo stalk.

I wouldn't recommend using a bushhog or shredder to cut the bamboo.
Any knot or joint, left behind, would likely sprout. Running bamboo/
yaupon is a prolifically invasive grass specie.

You will have one heck of a job removing all the above ground bamboo
debris, no matter what you do to cut it. Do a little at a time.
It'll eventually get done, unless you can afford to do or have the
whole job done, at one time.

Sonny