Answers 1a.Excessive irrigation can cause a N deficiency which can cause yellowing. The obvious solution is fertilizing. It may be Fe but my money is on a Mg deficiency. To find out, grab some Epsom salts at the grocery store, mix up in a hose end sprayer and apply to a section of the turf. You may be amazed at the change. Nearly overnight it seems. 1b. I always liked Lesco 32-0-10. Unless you run a soil test and get a known P deficiency, you souldn't be adding more. It also contains 5% Fe I think. 2a. First pic is Live Oak seedlings. The acorns fall on the sidewalk, get pushed to edge, drop in the soil and germinate. 2b a weed tree seedling. 2c Grassy weed of some sort but the picture is really bad. 2d Broad leaf weed. A good pre-emergent like Simazine will go a long way to reduce you weed problem. You can use 2,4-D on SA as long as it has no other additives. I understand your frustration with the weed control company but I suggest you find a reputable one that knows how to take care of SA. Without certain pieces of equipment like a sprayer, it is nearly impossible to do a uniform chemical application. 3. Residual Brown Patch from last year. Use PCNB or any fungicide containing Propiconazole in late summer or early fall this year. 4 Bare spots are the result of inadequate sunlight and root competition from the tree for moisture. Mostly lack of light. If you can't grow weeds, grass surely will not grow. Expand/ new landscapecreate

I don't know what you read but St Aug is very easy to manage. But before I go on, is that an oak tree buried up to its neck in soil or mulch in that picture??? That tree, oak or not, needs to be unburied so that the roots are visible on the surface. Tree bark is not meant to be buried and becomes susceptible to a fungus which will kill the tree. And yes, that looks like a disease process going on. I have been very successful using corn meal to solve my annual disease issues. The application rate is 10 pounds per 1,000 square feet. There are two problems with using chemical fungicides. One is that in Texas the temperature is never low enough to apply. The other problem is that having healthy fungi in your soil is absolutely critical. When you apply a fungicide, you can't help but disrupt the soil food web and turn your healthy soil into unhealthy soil. It also looks like you're mowing too low. What did your book tell you about mowing St Aug? And did it distinguish between sun and shade? Out of curiosity, what did your book say about watering depth and frequency?

Your instinct about the disease was correct. Now that it's too late, go back and reread the directions on your fungicide to see if you can apply with temps above 90 degrees. Most are only good up to the low 80s. I'd hate to see more damage come to that lawn. There is a natural method of disease control that works well for my St Augustine. Corn meal attracts a fungus called Trichoderma. Trichoderma is a predatory fungus that feeds on the disease fungi. It takes 3 weeks to see improvement but I've been using it every year since 2002 with good results. I water 3 times a week at 35mins per station due to it being 100 degrees and no rain in sight here in East Texas. That's weird because with our drought restrictions during 2014 we were only allowed to water once every 2 weeks and we made it just fine. My preference would have been to water once a week, but the water police were enforcing the restrictions. The reason you got the disease was too much water. If you had been watering during the rain events of 2015 you might have set this up. The watering schedule that works all over is called deep and infrequent watering. Deep means 1 inch all at one time. My sprinkler can only put out 1/16 inch in 35 minutes. You'll have to measure your own because everyone's is different. Put out some cat food or tuna cans and time how long it takes to fill the cans. That's your new time for watering. Note that every zone might be different, so you'll have to measure every zone. Infrequent means no more than once a month with temps below 70 degrees. With temps in the 70s water once every 3 weeks. When the temps get into the 80s go to once every 2 weeks. In the 90s go to once per week. With temps above 100 you can go to once every 5 days. Mowing height makes a big difference. It appears you're okay and mowing at the mower's highest setting. Perfect. At my last house I let the St Aug grow up as high as it wanted. It stops at about 32 inches high, but I had one spot in the shade of the house and an oak tree where I had stopped watering in October of 2011 and sold the house last summer without ever watering that spot. It survived from rainstorm to rainstorm during a 3-year drought. So I'm not feeling your pain about the 100 degree heat and no rain in sight. This watering plan came to me via Phoenix. East Texas is positively soggy compared to Phoenix.

Good point about the shade. Can you post a mid day picture taken from, say, across the street, showing how much shade you get? Generally St Augustine will spread about 2 inches per week when the temps are in the 70s if everything is going well. You applied a chemical fertilizer waaaaaay too early even for the Woodlands. I just read Randy Lemmon's website recommendations. At first it sounded fine, but he gets into preventive treatments for disease, which I STRONGLY disagree with. Your soil requires a healthy population of beneficial fungi to be healthy. Treating it for no reason kills off the beneficial fungi and destroys the soil biology. Then looking at the rest of his suggestions it appears he's selling fertilizers just like Trugreen is. He's just not applying it for you. And he's selling far too much. Growing great St Augustine is really easy. Water deeply (1 inch all at one time) but infrequently, mulch mow at the mower's highest setting every 1-2-3 weeks (depending on how fast it's growing, fertilize once in early May (for the Woodlands) and again on Labor Day and Thanksgiving. You do not need to core aerate. As you pointed out it's hard work. You can do a much better job by spraying the lawn with shampoo at a rate of 3 ounces per 1,000 square feet followed by deep watering. Then 3 weeks later you can reapply if you think the soil has not become soft enough. I sprayed mine in 2012 and after a rain like today it's almost too soft to walk on without turning your ankle. If you want to get rid of weeds, wait until April and spot spray the weeds with an atrazine product. Be careful to read the directions 2 times. You should only spray atrazine once a year so make it count. It will kill just about everything except the St Augustine in 3 weeks. The odd thing about spraying it is you have to walk backwards so you don't walk through the stuff you sprayed. Atrazine is not a friendly chemical, hence these warnings. After a decade or so of doing these lawn care forums I'm willing to go out on a limb and proclaim that most people do not water properly. I mentioned deep and infrequent. Deep is 1 inch all at once. Infrequent depends on the temperature. With temps in the 90s you only need to water once a week. Yes, even in the Woodlands. And yes, even in Phoenix. With temps in the 80s deep water once every 2 weeks. With temps in the 70s water once every 3 weeks. With temps below 70 you can water once a month. This is probably the most important part of lawn care. Once you get the water controlled, then the mowing and chemicals (or organics) will work better for you. I have become full organic and have seen some benefits. If you want to continue with full chemical fertilizers, I would suggest at least once a year you apply an organic fertilizer like corn meal or alfalfa pellets (rabbit chow). These materials feed the microbes living in the soil and make everything work better. These are quite often all it takes to make poor soil healthy again.