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.

There is not a lot to learn for any specific turf, but there is a lot of discussion here and elsewhere about other types of grasses. St Aug is different because it spreads very fast when the temps are between 70 and 80. When it gets warmer than 85 or cooler than 70, it will maintain its range, but won't spread much. In my climate in the Texas Hill Country and south to San Antonio and further, it warms up through the 70s quickly in the spring and then drops down quickly in the fall. So we have two periods when it spreads. It will spread 5 feet easily during each of those periods, though. Sometimes we have longer periods of temperate and it spreads longer. I'd guess it spreads about a foot a week, now that I think about it. Inch a day easily. So you already have a fully filled out lawn, but if it gets damaged, now you'll know that it will recover. Basics of Lawn Care After reading numerous books and magazines on lawn care, caring for lawns at seven houses in my life, and reading numerous forums where real people write in to discuss their successes and failures, I have decided to side with the real people and dispense with the book and magazine authors. I don't know what star their planet rotates around but it's not mine. With that in mind, here is the collected wisdom of the Internet savvy homeowners and lawn care professionals summarized in a few words. If you follow the advice here you will have conquered at least 50% of all lawn problems. Once you have these three elements mastered, then you can worry about weeds (if you have any), dog spots, and striping your lawn. But if you are not doing these three things, they will be the first three things suggested for you to correct. 1. Watering Water deeply and infrequently. Deeply means at least an inch in every zone, all at once. Infrequently means monthly during the cool months and no more than weekly during the hottest part of summer. Do not spread this out and water for 10 minutes every day. If your grass looks dry before the month/week is up, water longer next time. If that does not work, then you might have to water more than once per week during the summer's hottest period. Deep watering grows deep, drought resistant roots. Infrequent watering allows the top layer of soil to dry completely which kills off many shallow rooted weeds. You will have to learn to judge when to water your own lawn. If you live in El Paso your watering will be different than if you live in Vermont. Adjust your watering to your type of grass, temperature, humidity, wind, and soil type. It is worth noting that this technique is used successfully by professionals in Phoenix, so...just sayin.' The other factors make a difference. If you normally water 1 inch per week and you get 1/2 inch of rain, then adjust and water only 1/2 inch that week. 2. Mowing Every week mulch mow at the highest setting on your mower. Most grasses are the most dense when mowed tall. However, bermuda, centipede, and bent grasses will become the most dense when they are mowed at the lowest setting on your mower. In fact there are special mowers that can mow these grasses down to 1/16 inch. Dense grass shades out weeds, keeps the soil cooler, and uses less water than thin grass. Tall grass can feed the deep roots you developed in #1 above. Tall grass does not grow faster than short grass nor does it look shaggy sooner. Once all your grass is at the same height, tall grass just looks plush. 3. Fertilizing Fertilize regularly. I fertilize 5 times per year using organic fertilizer. Which fertilizer you use is much less important than numbers 1 and 2 above. Follow the directions on the bag and do not overdo it (unless you use organics in which case you may overdo it without fear of hurting anything). At this point you do not have to worry about weed and feed products - remember at this point you are just trying to grow grass, not perfect it. Besides once you are doing these three things correctly, your weed problems should go away without herbicide. I wrote that a couple years ago as a FAQ for noobs. I'd like to add something about watering for St Augustine. Watering is the most important part of lawn care. If you do it wrong you can get diseases and weed problems year after year. Deep and infrequent is the mantra. Put some tuna or cat food cans around your yard and turn on your sprinkler(s). Time how long it takes to fill the cans. That will be your watering time from now on. How often you water depends, as it turns out, mostly on daily high temperature. With temps in the 90s, water deeply once a week. With temps in the 80s, water deeply once every 2 weeks. With temps in the 70s, water deeply once every 3 weeks. The rest of the year water once every month. If you have a week above 100 degrees, water every 5 days. If you go a month or so without any water in the summer, St Aug can dry out and turn a golden color. It's still alive but just barely and will recover with some water. Once it turns tan it's toasted and gone. So there's a lot of leeway.

Since your neighbors all have bermuda, you're going to have to ignore their maintenance practices. Bermuda is about the opposite of other grasses. It needs fertilizer every month and very low mowing twice a week. You can just sit back and watch them work. You sound like a relative newby to St Augustine and possibly to lawns altogether. Here's what you need to know about watering. The watering mantra is deep and infrequent. Again, this might run contrary to your neighbors even though it should not. Deep means 1 inch all at one time. Don't spread it out over the week. Time how long it takes your watering system to apply an inch by setting several cat food or tuna cans around the yard and timing how long it takes to fill them with water. My oscillator sprinkler with my hoses and water pressure takes 8 hours to fill them. My neighbor's high flow system takes 20 minutes. You'll likely be in between those extremes. Once you know how long it takes to fill the cans, that's your watering time from now on until something changes. Infrequently means you let the soil dry out completely before you water again. There are many factors but the one factor that seems to dominate is air temperature. When temps are below 70, water about once a month unless it rains an inch. With temps in the 70s water once every 3 weeks. Temps in the 80s water once every 2 weeks. Temps in the 90s water once every week. Temps above 100 water once every 5 days. If you have prolonged temps above 110 water every 4 days. THIS WORKS! It works in Phoenix and it works in Vermont. Simply fixing your watering schedule can resolve lots of lawn issues. It likely will allow your grass to remain green longer in the fall before dormancy. So ignore what your neighbors do with their watering frequency. One more thing about St Augustine. When the air temps are in the 70s it will spread over the surface of the ground. It can grow an inch or two per day as long as the weather is mild. You'll notice it most around the borders of the lawn. One other thing about St Augustine is that it is prone to fungal disease if you cut off the air flow around it. If you have kids, don't let them leave big toys out laying on the grass. My wife likes to prune the garden and toss the clippings on the lawn. Well, I've finally raised her awareness to this, but before that it would get disease every year. Corn meal, as you have already mentioned, is the solution to this. And another thing in general, if you listen to Howard Garrett on the radio and have questions about anything he says, please ask for a second opinion here. I am the (seldom seen) moderator on his lawn forum, and I do not always agree with his recommendations. He's more of a salesman than I am. He's got a product for everything, but sometimes just good practices will fix the problem.

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.