St Augustine is extremely sensitive to having the air shut off above it. If that is what you have, you could treat the yellow/dead looking areas with corn meal at a rate of 20 pounds per 1,000 square feet.

I should have asked where you live. SoCal or NorCal are not nearly explicit enough. Calif has too many soil types and microclimates close together for those to work.

Interesting...how does corn meal help?

If it is a fungal disease, which it would be if this is St Augustine, corn meal attracts a predatory fungus called trichoderma (try koh DER mah). The trichoderma builds up on the corn meal as it decomposes. Once the corn meal is decomposed the trichoderma takes off and kills out other nearby surface fungi. I have used it successfully every year since 2002 on my St Aug.

Corn meal has some benefits for lawns.

It is said that corn meal is good for fungal control. This has been greatly debated over the years and it has more NO than YES votes.

It is good for soil conditioning and feeding your lawn. It may do it. But I have not found enough evidence backing it to go out and start applying it to the lawn yet.

Learn to make compost tea and does the best job if you are into organics.

hippy, It would seem that there is no chemical fungicide at all safe to use in the summer heat. If you think you have a fungus issue, the only thing left to use is organic. The organic community has been very satisfied with corn meal for nearly 20 years now. I'm not sure how greatly debated it is, but corn meal is the only reason I have a lawn. It was being consumed by fungus for all of 2001. By the time I tried the corn meal I had all but given up. Three weeks after the corn meal, I had new grass growing where it had been dead for months.

Compost tea cannot be made in the summer. The purpose of compost tea is to extract beneficial aerobic microbes from compost, feed them in the presence of bubbled oxygen for 24 hours, and immediately spray that tea on the garden. The problem with doing that in the summer is that water at temperatures higher than 80 degrees cannot hold enough oxygen to support any aerobic biological life. It doesn't matter how much air you bubble through, the fact of chemistry is that warm water cannot hold enough oxygen. As soon as you put the compost into warm water, the beneficial aerobic microbes begin to die.

Interesting. I've never heard of cornmeal for lawns before!

I live in Northern California, near Sacramento. Hmm... I wonder if my grass is St. Augustine.

+1 on the corn meal. Although I find it's better as a preventative than curative (my fungal shield went down in early May and with daily rainfall I'm the only one without brown patch and Pythium blight again this year).

Raise amounts for a curative to 20 pounds per thousand (10 per K is sufficient as a preventative) as David mentioned.

Are either of those plastic pieces partially transparent--and the old one was opaque? It's possible you accidentally solarized the grass, which really dislikes temperatures over 120 or so. I have some difficulty with the area three feet around my driveway due to solarization effects during the summer, although in winter that area never really stops growing due to the heat--and that doesn't trap solar energy in a solar greenhouse the way a semi-clear plastic will.

If the roots got baked, there's no cure for solarization. If just the tips did and the roots are OK, generally watering appropriately will bring it back.

It's actually very simple. Slip and Slides and kiddie pools cause two issues. #1 Create an environment which doesn't allow the turf leaves to properly transpire, thus literally cooking the turf. #2 No light.

#1 is the primary culprit in the warmer months and for some turfgrasses, it's a death sentence; for others just a 'burning' of the topgrowth. In California's many climates ( not the desert ) most any turf type will do well if given the right maintenance. As most residential turf in California is tall fescue, the odds are that this is what you have. Unfortunately TF's very likely not to survive either a slip and slide or wading pool ( if left on the turf for a period of a few days ). Especially in high heat. For grasses that feature underground rhizomes; ie KBluegrass and Bermuda, they too will burn but will recover with time.
Bottom line, it has nothing to with what the products were made with, or the soil, or fertilizer. It's just been 'smothered' to death! Next time just don't leave the play toys on the lawn! PG78

I had the same problem with the slip n slide I purchase at wal mart (not that it is a bad thing), but it was only on the lawn for 2 hours if that, and after the grandkids and I used it, I hung it up on the clothes line to dry. It was not brown when I picked it up but was the next day. Only two hours!!!