Some things this city boy has learned about weeds here in the jungle of central Missouri...
1. You can't stop them, the key is finding what level you want to live with them. They overgrow my gravel driveway for fuck's sake. I've tried Roundup (which works the best of all the types of herbicides that I've used on perimeter sprays) and it helps keep them down but applying that shit on a perimeter around 5 acres is some hard work man. So I have settled in to using it in the spring and into the early (wet) half of summer on an as-needed basis. And by the way I've also used salt, vinegar, etc. None of that shit works out here though and the plants are like "that all you got MFer???"
2. I wouldn't use chemical on a vegetable garden personally. Don't have the garden beds in just yet but going to go with raised beds that will be ready for next spring and my whole purpose for doing that is to get away from chemicals they put in shit. I doubt I'll grow enough to keep us in food through the whole year so sticking to my guns on the herbicide is kind of important to me. Also and this annoys the shit out of me but the bugs are a whole other problem once you actually start growing food. I found this out when my apple tree hit year number 3 and is now covered with apples finally, however the bugs (and the birds too for that matter) have been feasting on them. Not sure how many will survive and I'll adjust from there but I still don't think I'm going to be willing to spray even my fruit trees with chemicals.
3. Elbow grease is the best remedy IMO. Pulling the weeds or at the least weedeater usage to keep them down is my primary way of control. The gravel drive the best way is to drag a blade from a tractor or other heavy equipment and re-spread the rocks. That buys me a year when I do it. In my wife's garden (which is massive by my definition of a garden) the mulch itself was what introduced a lot of nasty weed types along the paths and on the paths, all of which has to be pulled if you want to get rid of it. Oh and btw my wife swears by a coconut mulch she uses now, swears it doesn't have the weed seeds in it like the other stuff had. So I get out there with one of those rolling low seat things and wear a good pair of gloves when I help her out.
Seriously though I even tried a flame thrower attachment for a BBQ grill propane gas tank. Went around the trouble areas nuking the everloving shit out of the weeds and they were back the very next week even stronger. I swear man if humans disappeared in like one year the entire midwest would be a thriving forest growing up and through the houses. It's just crazy.