>>2791988get yourself a mattock like picrel. its by far the most useful tool for weed stomping, one swing at the ground takes out any weed assuming that the "trunk" is narrower than the handle (just an estimation). aim about 5cms below the ground where the plant is coming from
saws are a waste of time unless you need to take down a tree taller than you are, and then also need to carry it out. otherwise just mattock the roots and knock it over and leave it