Crab grasses are a real problem in Texas. Up where you are...I can’t remember the name of the tall, grassy weed... but if you pull it out wrong, it sprouts more and more tall grassy weeds. UGH. I lived a little north of Dallas and nothing short of crawling around on hands and knees performing extensive weed extraction helped get rid of those things.
It’s been so warm this season that grass is now starting to grow in San Antonio and my neighbors on either side are popping crab grass that is seeding like crazy. It’s all I can do to keep it from my weed free lawn. The birds are nesting and my begonias never faded from summer!
Good luck and welcome to Texas!!
Dallas grass and the long grass sounds like Johnson grass. Johnson grass have roots, long, long and deep roots. I use Roundup and completely cover from tip to ground. I had one devil of a time in one of my raised gardens. Evidently I’d put it right over some Johnson grass, and it took over the okra the first year. We carefully pulled the okra, at the end of the season I then cut each grass down the doused each stub with Roundup. Now I’m fighting thistles..with Roundup.