>>2361767What are the weeds that need killing? Roundup is a non-selective glyphosate herbicide that will kill everything it touches including your lawn but isn't dangerous. TruGreen or whoever will probably identify the pest plants and recommend some kind of selective broad-leaf spray with bromoxynil like pic-related.
Just go to a garden supply store with a sample of weeds you've dug out and ask the plant wizards. Spend maybe $150ish on a pump pack and enough herbicide to last a year or two. Go out and spray them when you don's have any rain forecast for a couple of days. Spray them in the morning and they're toast by the afternoon