You're mowing st augustine too low. keep it at 4 inches during drought.

Forget turfallo. See if you can get FLoratam St augustine pieces (where do you live in Houston? You can get them at Buchanan's Nursery which is very drought hardy in full sun. Probably much better than what you have. I wouldn't be surprised if you have Raleigh variety which has very poor drought tolerance. Most years, Houston gets enough rainfall anyway on everage of 45 inches a year! My mom's lawn in houston never gets watered and her lawn looks fine. It's all about having healthy soil, you know full of earthworms, etc. No pesticide over the entire lawn that would harm earthworms. Organic fertilizer is used. You have millions of holes in the ground from earthworms and can easily absorb sudden heavy downpour without water run offs like other lawns that is hard panned soil from excessive usage of chemicals.

How do you water? You need to water slowly and deeply. 1 inch is 600 gallons of water per 1000 sqft. Use tuna cans to find out how long it takes . I use 5g bucket to put sprinkler in and time it to find out long it takes to fill up the bucket. My sprinkler covers 20ft by 20ft (400sqft) and it takes around an hour to put down 1 inch. You can see how long it takes to water the entire lawn deeply. Light watering few times a week is a huge waste of water. Most of water will be evaporated with no or little benefit to grass.

when rain returns, st augustine will just take over turfallo. Turfallo is not that fast grower at all. Stick with hardy Floratam st augustine if you can find them. Big box stores won't have them.

Here is a link that might be useful: Floratam st augustine

You don't want any kind of Buffalo grass in Houston, besides it is very expensive. In Houston you likely have heavy gumbo soil. The soil combined with the normal rainfall Houston receives will kill off buffalo grass with weed invasion.

my sprinker covers about 50x20. i divide the entire yard into 4 sections. i have a corner lot, a bit bigger than the other lots. i'll water section 1 on day 1, then section 2 on day 2, etc. then wait the next week and repeat. i water for an hour to hour and 15 mins.

i have my mower set to the highest setting, its an MTD from home depot, i think its either 2 3/4" or 3"

this home was built in 2000 and we bought it in 2007. dont know anything on how the previous owner cared for the lawn. i've been working mostly on the front lawn, got most of the weeds out. no chemicals, i use a sharp knife and cut the weeds out by the roots. but the dying SA is leaving open spots for some weeds. there were a couple of patches 6x6' of dallis grass that i dug out and bought some SA sod.

in the backyard i have a couple of large patches of dallis grass. so far i have dug up 2 of the smaller patches and sodded with the SA from the houston garden center. dont know the variety. but i will check out buchanan's, i have heard of it before.

my parents and my aunt/uncle have SA lawns, had their houses for over 30 years and they dont water the lawn and its perfectly fine. i guess they have the floratam var.

this spring i bought quite a few bags of composted peat and did a light top dressing. i'll top dress a little heavier once the weather cools down a bit, prob in october. we have dense clay soil(beige color). i dont bag any of the grass clippings. i just leave it on the lawn.

after reading the link on floratam, my parents do not have that variety, theres absolutely no purple on their SA.

Why don't you plant Bermuda in the full sun areas and leave St. Augustine in the shade since you're already having success there?

Empire Zoysia looks a lot like some St. Augustine, you might want to try that in full sun, but it is expensive to sod, plug, or sprig. I believe Zoysia is more drought tolerant than St. Augustine, but I'm sure someone will disagree with me.

Down here what makes a plant drought tolerant is the ability to go dormant with a lack of water. Zoysia can do that. St Augustine cannot. Thus St Aug shows up poorly in any drought tolerance comparison.

auteck,

you're completely wrong. Floratam st augustine is more drought tolerance than zoysia grass, ALMOST AS GOOD as bermuda! READ that link I provided! Floratam went 60 days without water and had 90% recovery. Zoysia grass is in the 60-70% range recovery after 2 months of no water.

Bermuda and st augustine require difference maintenance, why even bother? That's very poor advice.

Houston Texas,

I'm pretty sure Houston Garden Center sells Raleigh variety. I often go there to check out plants whenever I visit family in Houston. Buchanan is a nice place. Interesting plants that you won't see at Houston Garden or big box stores. They usually have fresh Floratam sod every Friday if I recall.

Here is a link that might be useful: Buchanan Nursery

If you are having such a severe drought right now and your water bill has already went way up, I would not do any lawn renovations or even come close to spriging or plugging. Establishment will be not be fun when you look at your water bill. And it may be prohibited right now.

Second, Putting bermuda and St aug together is a nightmare! You might as well have crab grass. That might be a little stretch. But if you put bermuda with the St aug, once the drought is over and you are mowing at 2 1/2 inches, you will just have St. Aug thoughout within a couple of years and terrible looking rope runners fingering it's way through out the Bermuda. Just a bad mix. Oil and water.

Wait until there is a normal wet year in your area and plant the most drought tolerent grass.

I do need to repeat though, I would not renovate during a drought or water rationing. Just remember this drought next year when Tropical Storm Zoysia hits and renovate your lawn then to make it more drought tolerent for the next drought.

I have a relatively fast growing zoysia but once it dies or goes dormant, it's brown for the rest of the season. It is still alive but only underground. The fact that it is alive gives it the official moniker of being drought resistant. Mine also goes dead/dormant without warning. That's not a good turfgrass for hot areas. My variety is called Shadow Turf. Hope that clarifies what I said about zoysia earlier.

I agree that reestablishing grass during a summer of drought is a steep uphill battle. I'd wait until the weather at least cools off.

agreed, i have no immediate plans to sod my lawn. but i am collecting as much information as possible atm.

thanks for all the input

If you are planning ahead, good. Look for sources of Floratam and take notes. In the mean time take the best care of your lawn as you can. Water as much as you are allowed (once a week for as long as you need or are allowed), and mow at the mower's highest setting. Let it get longer (unmowed) if you can. Then deal with mowing the taller grass down after the rains return. Fertilize about now with any kind of fertilizer. If you want to use organic fertilizer you can do that any time and repeat often.