Hi Tricia. It always seems to be that someone will come into a forum stating they are already doing some things correctly and then state what they are doing...which is incorrect. Now who's really to say what is correct and what is not? In the case of mowing St Augustine, there is ONE height to mow. That height is the maximum height your mower will go. There is NEVER any reason so lower the height of St Aug...unless you are trying to kill it out. For all practical purposes you can set your mower to the highest position and weld it there. If you can find a mower that will go up to 6 inches, that is great! Most mow to 4 inches.
As for watering, deep and infrequent is the mantra I started many years ago. I learned it from a lawn professional in Phoenix where he was using it. All I have done is made it popular. Deep means 1 inch all at one time. Infrequent means monthly in the winter and up to every 5-7 days in the hottest heat of summer.
I am doing a St Augustine experiment down in George West. I have a great St Aug lawn around the house and am letting it go unmowed. Unfortunately I decided to do that late in the growing season (about November), so part of the lawn had been mowed. The grass that has not been mowed since September is about knee high and looks great (if you like tall grass). The rest of the lawn is dormant from the cold. When the grass comes back in the spring I plan to not mow and see how that works. My lot is an acre and I'm there alone so I don't have others urging me to do things differently. This is what it looked like in October. My side of the fence is not mowed while the neighbor had just mowed. Also I had only owned the house for a month. The lawn has not been fertilized in years.
About fertilizers, if you check the ingredients of any bag of good organic fertilizer you will see the following ingredients: corn meal, corn gluten meal, feather meal, alfalfa meal, soy meal, wheat meal (flour), cottonseed meal, and a few other materials otherwise known as food. You can buy the commercially branded organic fertilizers for $50 per bag or you can visit your nearest feed store and buy twice as much of the same ingredients for about 1/3 the cost. This simple bit of advice has launched hundreds of thousands of people into organic lawn care. What scared everyone up until the early 2000s was the high cost of compost. Well, as it turns out, compost is not the fertilizer that Rodale and others have told us it was. Food is the fertilizer we should have been looking at. Cheap food comes in plain brown bags at the feed store.
Here is a picture of a piece of zoysia lawn "treated" with alfalfa.
The picture was taken in June after applying alfalfa in early May. The grass is obviously greener but also much more dense. Given that applying food works, where do you get the most bang for your buck? Soy bean meal has the most protein per pound of any of the popular products. Corn gluten meal has more protein but has usually been priced higher than soy bean meal. In fact in many places in Texas one or the other is simply not available, so you might have to go with alfalfa. In your area you can likely get either one. This year corn prices have exploded. I used to get a bag of corn for $3 but this year it was $17. Soy bean, which used to be expensive at $12 per bag, was looking pretty good. Corn gluten meal is about 60% protein while soy bean meal is 40%. Alfalfa is much lower in protein (about 15%) and ordinary corn and coffee grounds are much lower than that (around 6-8%). So the best one to use is the one that gives you the most protein per dollar. The application rate is anywhere from 10 pounds per 1,000 square feet (which is a starvation diet) to 80 pounds per 1,000 (which is enough to smother your grass with kindness). A happy medium is 20 pounds per 1,000 applied as often as you can afford to do it. For St Aug it will love it if you apply at 30 pounds. It will become very dense, dark green, and it will not necessarily spurt growth like a rocket. Timing is as often as you can afford. Easy dates to remember are Washington's Birthday (next month), Memorial Day, 4th of July, Labor Day, and Thanksgiving. I call that the Federal Holiday Schedule for lawn fertilizing. It only works for organics because chemical ferts can kill a lawn in summer heat.
Last year at my other home in San Antonio, I applied corn gluten meal every month at a high rate. My lawn has never looked that nice. Apparently I had been starving it. This year I am going to apply at the same high rate but only every other month starting next month. The other part of the tall grass experiment in George West is to not fertilize and also see about cutting way, way back on watering. We'll see how that works. By the way I have seen unmowed, unfertilized, and unwatered St Augustine flourish through long droughts, so this is more of a verification than a real experiment.