The first problem we have is one of naming. Herbicides, and other commercially-marketed chemical formulations have three names; first is the IUPAC (International Union of Pure and Applied Chemistry) name; the name actually tells you the structure of the molecule and is the internationally agreed-upon chemical name. For example, 2,4-Dichlorophenoxyacetic acid is commonly called 2,4-D for short. The IUPAC tells you that there are two (Dichloro) chlorine atoms substituted on its phenol ring at the 2 and 4 positions, and that it has an acetic acid on the 1 position. 2,4-D is it’s Trade name. Trade names are agreed-upon shorter names by the industry – because who wants to say “2,4-Dichlorophenoxyacetic acid” every time? Then there is its Brand name, assigned by the company that sells it. In this case. 2,4-D is sold as Killex, Trimec, End Run, more than I can name. It’s the least useful name, because each different company can assign its own brand name, and can even change it – but it’s still 2,4-D. Brand names are a marketing thing.
Crossbow is a mixture of 2,4-D and Triclopyr (3,5,6-trichloro-2-pyridinyloxyacetic acid). If I want to know what I’m buying, I read the ingredients.
Then there is a similar problem with names of the plants you are trying to kill. They have Latin names that tell you the genus and species of that genus, and for each, they will have a common name. Common names can vary locally for each region, state or country. “Ironwood” is a common name worldwide, and very few of them are related to each other. It’s just whatever wood that grows nearby the user, and denotes the hardest wood in that area. “Stiltgrass” is also a common name; others for it are Japanese stiltgrass, Nepalese browntop, several others. Here is the USDA catalog of invasive plants: https://www.invasivespeciesinfo.gov/terrestrial/plants/japanese-stiltgrass Its Latin name is Microstegium vimineum. I’m not going to suggest that we all look up the Latin names, but it would prevent confusion.
As for what kills your particular problem, you may have consult with your State or County biologists. I know that (trade name) glyphosate (brand name Roundup) will kill most North American plants, but some of the Asian species just laugh at it, don’t even turn yellow. I have had some limited success using dilute 2,4-D to kill weeds in my centipede lawn, but it’s not recommended for use as a selective herbicide – too strong and you kill the grass.
Then there is method of action; glyphosate is a foliar treatment – diluted in water, you spray the leaves. But triclopyr works best in kerosene, diesel, even soy oil, that you dribble down the lower 12” – 18” of the trunk, all the way around it. They call that basal bark treatment. To further confuse things, the oil/petroleum diluent for triclopyr tells me that the cambium layer (between the bark and wood) is subject to non-polar solvents, as opposed to polar, like water or alcohol. Or maybe the triclopyr is, I still haven’t figured that out.
I’m in N. Florida; plenty of sunshine and rain. Everything from anywhere in the world wants to grow here, and will. I see something new every year, some weed, bush or tree that is not native, stuff I have no name for. I’m fighting a losing battle; I can kill the ones I find on my property, but I can’t kill all of them in the state. The State has an Invasive Plants bureau, but it doesn’t have the personnel or funding to go out and eradicate them. I kill what I can, even on public property, but herbicides are expensive, and the state won’t supply me with them, even if I provide the labor.
Finally, I have a special request: if you’re going after weeds in your lawn, please, PLEASE do not use the selective herbicide Atrazine on lands that drain into a body of water. It works quite well in controlling unwanted grasses, like at a sod farm. But my neighbor has a 20-acre hayfield she’d let go; the guy she hired to revive it six years ago used atrazine; it disrupts the ability of amphibians to reproduce. Her field drains to the stream that feeds my swamp; I haven’t seen a Cooter or a bullfrog in my swamp since then.