I agree. Milberger's Nursery inside Loop 1604 at Bulverde Road used to have Floratam Fridays. Check with them. I have Floratam in the back yard at my house in San Antonio, and it's so dense I can barely mow it. I can only cut 6 inches at a time. Compost in SA costs about $75 for a cubic yard which covers 1,000 square feet. That's the cost if you have it delivered. Or if you simply use alfalfa pellets from your local feed store, you can get a much better effect for more like $5 per 1,000 square feet. 50 pounds of alfalfa pellets (rabbit chow) covers 2,500 square feet. You can apply alfalfa 15 times before you come up to the cost of compost, and alfalfa is a real fertilizer. Any time is good for St Augustine sod. Do you not have any St Augustine at all? Because a few bare spots will fill fast if you have any living St Aug. I just bought a house in Bandera. It has a total (maybe) of 10 square feet of St Aug grass. The rest is weeds including horse herb and King Ranch bluestem (the stuff you see planted in Texas highway medians). I plan to grow out the St Aug to cover the entire lawn in a couple years. Once it starts to spread, it fills faster and faster.

If you could get your camera about 3 inches away from the grass instead of 30,000 feet, I could likely confirm a fungal disease. The best pictures of grass are taken in the shade or on a cloudy day to minimize contrast caused by the sun. If you get close you'll see tan spots surrounded by dark brown spots. That's the disease. I'm guessing you live in Texas and have received more than your average share of rain in the past few weeks. If it is a fungal disease it will get better about 3 weeks after an application of ordinary corn meal at the rate of 20 pounds per 1,000 square feet. You can get corn meal in 50-pound bags at your local feed store. If you cannot get it there look for a grocery store catering to the Hispanic community. Ask for (or find it yourself) corn flour. Don't get the premix used for making tortillas. It should come in 25 pound bags. I scatter it by hand. Flour tends to blow away, so you might want to use a drop spreader to apply it. And it tends to clog a drop spreader which is why I apply by hand. If it is a fungal disease and you live where the temps are in the mid to high 80s already, don't use anything but corn meal. If you live where it's cooler, you could use a chemical fungicide. I've never needed one, so I can't give you any hints. Corn meal has worked for my St Aug for the past 13 years. If you want to reapply after 3 weeks it won't hurt a thing. In fact if you want to reapply the next day it won't hurt anything either. This weekend is an excellent one, timingwise, to apply fertilizer anyway. Corn meal is a weak organic fertilizer. If you only use it on the affected spots, you'll have dark green grass there in a month. Corn meal works by attracting a predatory fungus as part of the decomposition. That fungus consumes the disease fungus and your grass will recover. If your lawn is in full sun, you might want to throw a couple pieces of Floratam St Aug sod down. It's a very fast growing variety that can actually outrun this particular disease. I see the disease in my Floratam, but it never seems to die out like yours is. I still hit it with corn meal because the spots are ugly.

You may have had bugs. Something at the root it appears. There are several. Clemson and several schools publish articles on the grass care.

I agree about the vigor of Floratam. In full sun it is very dense. The idea is interesting, but there are some problems. Bermuda seed must have hot soil to germinate. In San Antonio it is not hot enough for bermuda until mid to late May. Sure, I realize you can go anywhere and buy bermuda seed. It's on the shelves year round in SA, but it's only going to germinate in the hot summer. So that's one issue - the grass you are thinking of won't grow right now. Another issue is the dogs are going to run through and tear up anything you put in right now. Here's what I would do. This weekend I would buy a couple bags of shredded cedar mulch and put them where the bare spots are. Dogs like mulch, and shredded cedar is a good one. After your grass bounces back and you are mowing it, then I would rake up the mulch and buy a few pieces of Floratam sod and put them in the bad spots. The existing Floratam will eventually return, but it might take all season with dogs running through all the time.