Botanbill, while I appreciate, sincerely, your input, if you live on sugar sand dunes and he/she doesn't, things could be different. It sounds like you and the OP might be relative neighbors, but I've been here a loooong time. FL is one of those places where you can't assume anything about the soil in different parts of the state. Tampa is one of those places where if you guess, you're probably wrong. While I expect sand, there are a bazillion lakes and ponds around there. Those don't form on pure sand, so there's a strong possibility he/she has something else. jmandawg, Do you get puddles when it rains? Do you still water even if you get rain? That does seem like an excessive watering frequency. If you can get your grass roots retrained to grow deeper in the soil, I strongly suspect you can restrict your watering to once a week or even less often. But if you're on sugar sand, then botanicalbill is going to have more to say about it. When I backfilled my back yard I used what amounts to sugar sand. It's 8 inches deep at the deepest, which I realize your soil is probably 80 feet deep, but still - it's sand for the entire grass root zone. That sand grows the best grass I have. After 12 years of organics the sand is black when you look at it, but when you put it in a jar of water, all the white sand sinks immediately to the bottom and all the black organic stuff floats to the top. That grass gets watered once every other week unless it rains. So far this year it's only been watered by me twice. We got some heavy rains and it really hasn't needed more. jmandawg again, generally the world gets by watering deeply and infrequently. Generally that means watering one inch of water, all at one time, and doing it once a week when temps are in the 90s. Other factors to consider are soil type, soil depth, grass type, grass height (yours should be mowed at the mower's highest setting), shade, clouds, wind, humidity, organic content of the soil, and some others. After taking all this into consideration, there are only a few places where the general advice would differ. One of those places is the area from Green River, Utah south to the Mexican border and west to Indio, CA and east to Junction, TX. That area is different because the soil is often gravelly. The sand is coarse and really does not hold any water. If Florida is another location where the general guidance does not apply, I have not heard about it. But I am certainly willing to listen to actual experience of people who have tried to grow deep roots and still required frequent watering. I'm still interested in the soil conditions for jmandawg.

I think you have your answer already....too much, too little. St. Augustine grass tolerates moderate shade, being as good or better than other warm season grasses for shaded sites. However, under densely shaded conditions, St. Augustine grass develops thin, spindly turf. Cant tell just how much shade that fence is giving the grass. So long as fertility and drainage are adequate, St. Augustine grass tolerates a wide range of soil types. St. Augustine grass grows satisfactorily at a pH range from 5.0 to 8.5 It does not tolerate compacted or waterlogged soil conditions. I think you have to watch how much watering you give with a view to how much the weatherman is promising. Florida cloudbursts can put as much 4" - 5" on a lawn in a short time and hopefully, drainage takes it away. I think too at fencelines, its not always easy to arrange for good drainage when you don't want to put it onto your neighbor. With that in mind, I suggest you work with your neighbor about how to best drain the area so that neither lawn gets too much.

Where are you in Central Texas? The town would be best, but basically are you east or west of I-35? North or south of I-20? It's impossible to say from those pictures, but thanks for trying. The best way to take garden pictures is on a cloudy day or in the shade without a flash. Otherwise the contrast between sunlight reflections off the foliage and the dark shadows is too much. Also if you suspect a disease, then get down on your knees and take a picture from 3 inches away in an area where the grass is going from green to some other color. We need to look at the spots on the blades. You should have been deep watering about once per month for the past month and every 2-3 weeks prior to that. If you were watering once a week or more frequently, then a disease is very likely. The following is the skinny on watering a lawn. 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.

Ideally you should start a new topic. I believe you did not get a normal amount of rain this winter. Have you been watering? I ask because I see some nut grass in the pictures, and nutgrass prefers really wet roots. Once you start watering deeply and infrequently, the nutgrass should go away/dormant without doing anything else. Raise your mower all the way to the top. The top is around 4 inches, but it it is 6 inches, so much the better. Look up above in this thread to the picture of my back yard with the cat in it. See how the cat is nestled down into the grass. In fact, since this is your back yard, you don't have to mow it at all. St Augustine will grow up to 32 inches tall. It's not a lot of fun to play in, but the point is the grass will do very well even when left alone. In mid April spray the yard with this product from Walmart. Atrazine is the important ingredient. This herbicide will wipe out everything except the St Augustine and bermuda. Spray on a day with little wind, walk backwards when you spray, and walk into the wind so any wind carries the spray away from you. This is a leaf misting spray, not a soil drench. You don't have to spray longer where the weeds are. It takes about 3 weeks before you realize all the weeds are dead and gone. If you are watering deeply and infrequently, both grasses should thrive. Ultimately the St Augustine will march through the bermuda and choke it out, because the tall St Augustine provides too much shade onto the common bermuda. This will take a few years or you can buy new St Augustine sod to speed up the process. You should not ever need to reseed into bermuda. If you have bermuda and it's not doing well, you're doing something wrong and even new seed will struggle. Besides, for you in Covina the best time to put down bermuda seed is in late June and July. If you put seed down now it won't germinate until late June or July when the soil is hot enough. Two more things: First, spray your yard with baby shampoo at a rate of 3 ounces per 1,000 square feet. If your yard is 1,000 square feet, put 3 ounces into the bottle of a hose end sprayer, fill the bottle with water, set the adjuster on any spray flow, and spray it all out evenly until it is gone. You can use any clear shampoo - it doesn't have to be baby shampoo. Whatever Dollar Tree has and you like the fragrance is fine. Second, call these feed stores to see if they have corn meal, soybean meal, or alfalfa pellets (ask for rabbit chow). Get prices for a 50 pound bag. Any one of these materials will do, so pick any one you like and spread it at a rate of 15 to 20 pounds per 1,000 square feet. Corn meal will be the cheapest at under $10. If they quote you $20 or $30, they're talking about corn gluten meal, not ordinary cornmeal. CGM works, too, but it costs more. All these are organic fertilizers. I think I mentioned to wait until late May to fertilize. If you use an organic, you can do it NOW (two weeks ago). Your soil looks gray and not healthy. If you want to get a soil test, send it to Logan Labs in Ohio. I know UCR and UCD do soil testing in California, but Logan Labs performs more tests on the soil for less money than the universities do. Get the $25 test. Let us know and we'll tell you where to send the results for a free reading telling you all about the soil. As a side note, it looks like someone has topdressed your yard too many times with too much soil. The soil level looks about 1.5 inches too high. It should be down closer to the edge of the concrete. If you ever chose to renovate, you should be removing soil and not bringing in more.