St Aug is very forgiving for a good long time with not enough water, so...

What I would do with it already knit to the ground is to water deeply (1 inch) and watch it to see how long it goes. If it goes a full month without wilting AND if the soil is not moist at the surface, I would water again. It should be going dormant if you get temps in the low 40s. Dormant St Aug looks like it is diseased, but it will return just fine in the spring. Don't be concerned if the grass is not the first lawn to come out in spring. Just let it happen. At that point there's nothing you can do to hurry it along. Once it goes dormant it will not need more than natural rain water; however, I like to water once a month unless it rains. I am concerned about the soil microbes during the winter.

If you feel like you need to mow it short for the winter, go hunting or something. The grass does not need to be mowed low for the winter. If anything I try to leave mine as tall as possible. It seems to go dormant faster when mowed low. In my tall grass experiment the tall grass (30+ inches high) never went dormant in 3 years. It did stop growing, but never showed the gray color of dormancy. Grass at my current house is about 7 inches high and is not showing signs of dormancy yet. We're supposed to get temps in the high 20s this week so I'll keep y'all informed.

Thank you dchall! That is some good info. This is my first time using St. Augustine so I have a lot to learn.

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.