Depends on if you want to kill everything or not. A strong solution of Roundup will work, but will kill grass and all. I'd use Crossbow or Garlon. Just be careful spraying them if it's really hot, you can get some off-target damage.
Yep. Triclopyr is the main ingredient in Garlon. Crossbow has triclopyr and 2,4-D both. Ounces per gallon depends on which formulation and what you're trying to kill.Is "triclopyr" the active ingredient in Garlon? I am not very familiar with herbicides outside of "Roundup". I am pretty sure I have some "triclopyr" at the house. Do you have a recommendation of how many ounces per gallon?