This is the second time I've seen this this year. It was not 45 minutes, it was 4 to 5 minutes. Big difference, huh!? All you have to do is moisten the sod, not drench the soil 2 feet down. At this point you should probably not water until the grass looks dry. It's already knit into the underlying soil with all that moisture. Just let it go until you see the blades fold together. Then water it...for 45 minutes. Actually get some cat food or tuna cans and place them around the yard. Time how long it takes to fill those. Then water for that time next time you need water. It should be at least a week. The idea with watering mature grass is to do it deeply and infrequently. Deeply is 1 inch. Infrequently is once a month in the cool months changing gradually to once every week in the hottest heat of summer. You do have a fungal disease in the older grass. Those are disease lesions on the blades (excellent pictures, by the way). This is going to sound crazy, because it still sounds crazy to me, but down here people have good results simply washing disease spores down into the soil with soap. The microbes in the soil take care of the spores. The treatment is to spray with 3 ounces of baby shampoo or any clear shampoo. That is 3 ounces per 1,000 square feet. This is the same treatment as for hard soil. Spray it now and make that the last time you water for several days. But watch it very carefully. If new grass shoots get the disease after you stop watering, then you'll have to treat it. If your soil was graded, that is the perfect preparation for new seed or sod. Rototilling is the worst thing you could do in prep for grass. I disagree with doing it for a veggie garden, too, but for different reasons. Definitely grade instead of rototill.

Floratam. It would be Floratab if the guy had allergies that day. You can save it. What happened is it got a fungal disease. There is nothing you can do about anything until you get rid of the disease. If you pulled up the old sod and put down fresh new sod, the new sod would be dead in 3 weeks. Ask me how I know that!! Summer time in south FL is too hot for chemical fungicides, not that I would ever recommend one to anyone. The only practical solution, believe it or not, is whole ground corn meal applied at 20 pounds per 1,000 square feet over the entire lawn. When corn meal decomposes it attracts a predatory fungus called Trichoderma (try koh DER mah). It will take 3 weeks to see the improvement but by then the grass should be coming back strong, especially in the full sun. Floratam does much better in full sun than in shade, but it will be fine once the disease is over and done. If you want to continue with corn meal just to be sure you got it, that's fine. You can use corn meal any day, or every day, of the year. It won't hurt a thing. It provides a reasonable amount of fertilizer factor if you continually apply it. You should notice the yard turning deep green and all the new grass will be deep green. Here's what you should have done instead of watering 30 minutes per day. You should have watered at most, 10 minutes, 3 times per day, for 3 weeks or until the roots knit down into the underlying soil/sand. That might seem like 30 minutes per day, but when you spread it out it gives the moisture time to soak in and also evaporate in between. Now that you're where you are, you need to back waaaay off on watering frequency. Ideally this time of year you would be watering 1 inch, all at one time, per week. Measure 1 inch by putting cat food or tuna cans in the yard and turning on the sprinklers. Time how long it takes to fill the cans and that is your watering time from now on. Then shut off the water for a week or as long as the grass will go without looking wilty. If it looks wilted before a full week, then water it again immediately. It will develop deeper roots when you water like this and allow the soil/sand to dry out at the surface. Those deep roots will allow the grass to go longer and longer between watering. If it rains, don't water until the grass needs it. Rain is different from irrigation water and seems to allow the grass to go much longer than you would let it go from irrigation. By the way my oscillator sprinkler takes 8 hours to fill the cans, so be prepared for anything. High flow undergrounds systems can apply an inch in 20 minutes. Also you should be mowing at the mower's highest setting. There is never a reason to mow Floratam lower than the highest setting. If your mower can stand it you can go 2 weeks between mowing. The problem there is Floratam grows extremely dense and requires a lot of horsepower to get through it. Weekly should work, but even that might be too dense to get through for lower powered mowers and most electric mowers. Floratam was developed by the University of Florida and Texas A&M University. Texas A&M goes by TAMU here in Texas, so the name of the grass came from blending all that together.

You picked a doozy of a topic to reference. I don't think I've ever seen so many people piggybacking onto one thread. The spots you see on your grass are the same as those I posted in that other topic. The corn meal should help. Give it 3 full weeks. This is not a shade issue or a watering issue. St Aug will be thinner in the shade but it should be healthy looking with zero spots or yellow blades. Here's a picture of my lawn in San Antonio growing in deeper shade than you had. The point of this picture is 1) no spots, and 2) lots of shade. I took this picture to illustrate chlorosis in St Augustine caused by too much rain. The yellow blades in the center are from the rain. The point you cannot see is that this area looked horrible a month earlier from disease. You could see the soil, leaves, stolons, and spots on the few living blades of grass. Note that you can still see through the turf a little to the stolons underneath. If this was in full sun it would be so packed in the blades would be growing straight up. I'll get a picture of my new lawn in Bandera looking straight down. It's very hard to push a mower through that stuff. Okay I have to comment on the TAMU pamphlet on growing St Augustine. Generally when I see something from TAMU I read it and do the opposite. Truth! Here's my experience this year. I live in Bandera now, so think Texas Hill Country. Our temps ran in the mid to high 90s this year. We got our first rain on Memorial Day and it nearly washed my belongings out of the garage. It was 11 inches in 3 days with most coming the first night. That's too much rain so I was expecting to get some disease. I did but only about 1 square foot was affected. But since Memorial Day I have watering the actual grass one time. Fortunately we got some rain relief last week, so from June 1 to Aug 19 I did not water. Had I followed TAMU I would have watered it every 5 days. Had I followed my own advice (below) I would have watered it every 7 days. What the TAMU people did was over simplify watering, but then they went into too much detail on how to achieve the simple watering. Watering is slightly harder than they suggest but setting it up is easier than they suggest. Here's my take on watering after reading and moderating lawn forums for 10 years. Watering: Deep and infrequent is the mantra for watering. This is for all turf grass all over the place. Deep means 1 inch all at one time. Put some cat food or tuna cans around the yard, and time how long it takes your sprinkler(s) to fill all the cans. Memorize that time. That will be the time you water from now on. My hose, sprinkler and water pressure takes 8 full hours to fill the cans. Your time will likely be less. I like gentle watering. As for watering frequency, that depends on the daytime air temperature. With temps in the 90s, deep water once per week. With temps in the 80s, deep water once every 2 weeks. With temps in the 70s, deep water once every 3 weeks. With temps below 70, deep water once a month. Note that you have to keep up with quickly changing temps in the spring and fall. This deep and infrequent schedule works in Phoenix and in Vermont, so it should work for you. The reason for deep and infrequent is to grow deeper, more drought resistant roots and to allow the soil to dry completely at the surface for several days before watering again. If it rains, reset your calendar to account for the rainfall. I guess I should add that if it rains 11 inches, reset your calendar back by a month at least. Mowing height. If you read the topic you referenced you saw pix of my dog in the tall grass. (We found her and she's up at the new house in Bandera). From those pictures you can see that tall St Aug is pretty healthy. I seriously did not water, mow, fertilize, or weed that lawn from October 2011 through Feb of 2015. All it got was rainfall. 2011 and 2013 were drought years, and it thrived. Point is keep your st Aug as tall as you can stand it. Set the mower to the highest setting and weld it in place. Contrary to what TAMU says, mowing it low does not make a better turf. Fertilizing. If I was on a rigorous fertilizer schedule I would use organics 5x per year following the federal holiday schedule (Washington's birthday, Memorial Day, 4th of July, Labor Day, and Thanksgiving). If I was on a casual schedule I would fertilize on Memorial Day, Labor Day, and Thanksgiving. If you decide not to use organic fertilizer, I would still strongly suggest you use it at least once a year in addition to, or in lieu of, one of your fertilizer apps. The general experience of the universe of lawn care websites is that lawns that get no organics for 10 years or so will develop issues where the chemical fertilizer seems to not be effective. One dose of organics will reset the soil biology and the chemical fertilizers will work again. I think you can avoid that issue by preempting it. Organic fertilizer is much less expensive per 1,000 square feet than compost. The fertilizer is also much easier to apply than compost.

Focus on slow, steady growth which allows the trees to develop a sturdy root system which will later support abundant crops. No fertilizer Fertilizer pushes growth. And then you must prune more than normal.