Thanks!

Since you have many types of weeds, we'll start with what are easier to control, the broadleaf weeds. This late in the season, broadleaf weeds are probably all you can really get control of until next spring. You can start with 2,4-D, or a mix of 2,4-D and other chemicals.

There are lots of different brands and mixes out there, so I can't give you a rate. You'll have to look at the label. You said you wanted to use agricultural labeled chemicals, but buffalograss can be killed by high levels of 2,4-D, and an agricultural label may not list the mix rate for buffalograss, instead listing mixing rates for corn or other crops. I would suggest that you buy a bottle labeled for lawns, to get the correct rate. I suggest something like Ortho Weed-B-Gon Concentrate, which you can purchase at a big box store. A bottle will cover 18,000 sq ft, which would be more than enough for an average lawn.

Grassy weeds are more difficult. To control annual weeds, you'll want to apply a pre-emergent in the fall and spring. Pre-emergents won't kill what's already there, but it'll prevent new weeds from germinating. Weed seeds tend to germinate in the fall and spring, so you need to get the pre-emergents out on your lawn at those two times. Three pre-emergents I would suggest are Prodiamine (trade name Barricade) or Pendimethalin (Scott's Halts Crabgrass preventer) and Dithiopyr (Dimension). These products may be cheaper at the ag-store. You'll need to check the labels for the rates, but apply once in September, and once in Late March/Early April.

That should be a start to get you into next spring. What will be left will be the perennial grasses. It can get tricky to control these, and these are outside of my particular expertise.

Lindon, linking to other forums is a no-no here (and on just about every forum). About 10 years ago lots of people got banned from GardenWeb doing that. The reasoning is that the advertisers on GardenWeb/Houzz don't want to lose the user to someplace where they don't advertise.

To the OP, I assume this is a seeded variety of buffalo grass. Weeds in seeded buff is par for the course. The buffalo grass seeds are just another weed. If you have sand spurs then I would guess that you are taking absolutely no care at all to include no watering, no mowing, and no fertilizer - at least until recently. I understand that, because some people want a zero maintenance lawn and will sometimes use buffalo. You can get rid of the thorny plants by watering and fertilizing. Those plants hate care. Water heavily (1 inch) once a month and fertilize in late May, early September, and Thanksgiving. Mulch mow high once a week. You'll probably recognize this as lawn care...which may be what you were trying to get away from by using buffalo in the first place. But the consequence of ignoring it is weeds. For your area broadleaf weeds should be sprayed in mid April and again in mid September.

One way out of your situation is to get a hybrid grass like UC Verde Buffalo. That grass grows so dense that no weeds can get established. If you have some patience, you could get just a little UC Verde and let it spread. It spreads relatively fast - certainly compared to the seeded varieties which are freestanding plants which don't spread. UC Verde never gets seed heads, so it never looks shaggy. If it looks shaggy with seed heads, then you have weeds.

Sorry about that. I've edited my post to remove outside references.

Thanks Lindon. We don't want people getting banned again. There are ways to get your point across, but direct links are way too obvious.