I'm a few zones away from you so I'm guessing that you grow softnecks which I'm pretty sure behave the same as my stuff when it comes to harvesting. Normally, garlic is ready to harvest when the leaves have started to turn brown and shrivel and there are 4-5 green ones left on the plant.

Here it is usually ready for harvest from late May through late June depending on the variety. I don't know if you are in the humid or dry part of texas but here in the humid NC we harvest when about 1/3 -1/2 of the plant has browned out. Getting them out of the ground when it is dry is usually a problem here so we will harvest alittle early vs a little late. If you planted any Turbans They will be the earliest harvest.

I'm in Monroe, LA so maybe you can compare with your zone. My turbans, Shantung Purple, Chinese Pink, and Xian, are usually ready in the first week of May with the rest a week or so later. Also have several creoles, Creole Red, Ajo Rojo Creole, Burgundy Creole, and Spanish Morado Creole, and a few Music, Lorz Italian, and Siberian. None of it looks good this year.