You can't know how much trouble you saved yourself by writing in here before doing anything else. Your worst problem is you have dallisgrass, not crabgrass. Crabgrass would die normally at the first frost, but not dallisgrass. It is a perennial and will take over quickly if you don't stop it. Since it is a grass, anything you use to kill it will also kill your bermuda. But since you have bermuda, it will grow back without doing anything else. Your second worst problem is the St Augustine weed. It, too, will take over under certain conditions. You don't have to do those, but unless you go the extra mile, a properly cared for bermuda lawn infested with St Aug will always look weedy. Possibly the easiest way to get rid of it is to make it sick. That's easy because all you have to do is cover it with some newspaper and wet it down every night. Leave the paper on for about a week and you should start to see lesions on the grass blades that look like the spots on this grass. Once you see that you can peel the paper off and let Nature take its course. The disease will spread throughout the St Aug and wipe it out. Since it does not come back from seed, once it's gone, it's gone. Bermuda might get the disease, but St Aug gets it fast and furious. It will die out in a month or so. If you get a freeze before it all dies out this year, the disease will come back next spring to get the rest of it. The bermuda will fill in as fast as the St Augustine dies out. Now the problem you don't know you have, and the problem that could easily become your biggest problem, is seeding into your existing bermuda. DO NOT DO THAT. Bermuda needs no seed. Once you have it, you practically have it for life. The problem with seeding into it is that the seed is very nearly a different species of plant from the grass you already have. What you have is a very good hybrid called Tif 419. What you get in seed is a variety of common bermuda seeds. The two plants do not mix well together. And I happen to have a picture of that, too. The fine bladed grass is Tif 419. The coarse bladed stuff running over top of the Tif is an invasion of common bermuda. As with St Augustine, once you have a mix of Tif with common, it always looks weedy. Find the Bermuda Bible online and memorize it. There are things you should be doing all the time. I can summarize: Every month: fertilize with a high nitrogen fertilizer Every week: water deeply 2x per week: mow But get the BB, it will explain when not to do those things. For your shady area you do want St Augustine. If you get a dwarf variety you can mow at the same height as the bermuda. If you cannot get a dwarf, then it is best to mow St Aug at the mower's highest setting (4 inches). St Aug is much less intensive to care for: Memorial Day: fertilize with a regular fertilizer (not weed-n-feed) Every week after the temps get high: water once, deeply, and mulch mow high Labor Day: fertilize with a regular fertilizer Thanksgiving: fertilize with a regular fertilizer By the way, centipede grass is out of the question in Dallas' alkaline soils.

3 is absolutely not nutsedge. Not remotely close. (Be glad.) 5 is definitely buttonweed. You have my sympathy. I've read that the best way to control it is to tear it out whenever you see it, and mow short.

dallisgrass is a clumping grass. Dig out individual plants before they set seed. If you have large patches, remove seed heads, the kill or strip the patch, and seed or plant.

I dunno, that sounds...anecdotal to say the least. " Homemade remedies are seldom very effective in their application, otherwise someone would have taken the recipe and patented it years ago." Sigh. Homemade remedies vary in their effectiveness and, as with the soap and kelp we use around here, can be very, very effective. Companies certainly do offer the same thing and cover the much greater expense with pretty language, attractive labels with four-color printing, and expensive advertising. That does not necessarily imply the product is better, "patented" or not. But they certainly charge more because they're not offering their expertise for free. This particular formula? It actually does have a use and a sales niche. It's called "horticultural vinegar," which does work. In some cases. With proper care. Would it work on crabgrass? On some weeds, if young enough, done on a hot day, in full sun. Don't get it in your eye because corneal burns aren't fun. So wear goggles. Wash your hands before you remove said goggles. Twice. With soap. It's a decidedly niche product and one I don't, personally, use for just that reason. And I wouldn't bother with the salt. I'm not a hundred percent sure about the baking soda, either...if you do something with vinegar and/or sodium bicarb, leave enough time to make sure you can go back and re-treat with an herbicide. A good rainfall will interfere with either. What's the long-term impact? Not that bad, really. Soil toxicity is low unless you're really dumping it on and even then, it can be flushed out. I'd be just as worried about the acidity (which will dispel the soil calcium) as I would be about the sodium...if you were dumping it by the barrel-full. A gallon or so sprayed across your property? No biggie, sodium levels are not much greater than if you had used soap across your property. With the baking soda, it's the other way around; you're increasing alkalinity AND adding sodium. There it's more, but you'd have to measure the weight. I doubt it's going to be enough to be an issue, but make sure. A few cups per thousand square feet scattered? No problem. Ten pounds? Um...that's a lot of sodium. For the reseeding process, if you're working with areas that are crabgrass and nothing else, I'd recommend wiping the area clean with Round Up. Kill it all. Nuke it from orbit, it's the only way to be sure... For areas with St. Aug (or whatever grass you do have if David is correct), use whatever method makes you happy. But as I noted, leave enough time to go back with a grass-compatible herbicide if you must...