That's a fungal disease from over watering and hastened by the rain.

The universal mantra for lawn watering is deep and infrequent. Deep means 1 inch all at one time. Infrequent means once a week when the temps are in the 90s, every other week when the temps are in the 80s, every 3 weeks when temps are in the 70s, and once a month the rest of the year. I realize that everyone in Florida firmly believes they must water daily because they have sand and the water washes right through. Bull. Sure it washes deeper, but the grass roots seem to grow deeper, too.

Start by measuring how long it takes to water an inch. Put some cat food or tuna cans in the yard and turn on the sprinkler. Time how long it take to fill them all. That will be the first time the lawn was watered deeply. Then don't water for at least 2 days. Watch the grass for the first signs of dryness. At the first sign, water it another inch. Then watch and wait again. The grass roots will grow down deep enough to pick up the water much deeper in the sand.

As for your disease, since 2002 I have had success using corn meal. In fact the initial success I had with fungal disease on roses launched me into organic lawn care. Corn meal attracts a predatory fungus that devours the disease fungus. The process takes 3 full weeks to see the new grass coming in without spots. But corn meal is something you can use any time of year, as much as you want, as often as you want, without any fear of damaging anything. The application rate is 20 pounds per 1,000 square feet. Apply to the entire yard because corn meal is also an organic fertilizer. It will turn your grass green in the spots you apply it. You can get corn meal at feed stores (call first to see if they have it) or at grocery stores catering to the Hispanic market. At feed stores it comes in 50-pound bags. At grocery stores it comes as corn flour in 25-pound bags. Don't get the tortilla pre-mix. Also at feed stores, don't get corn gluten meal. Those are different items. Corn meal should be about $10 per bag at the feed store and $8 per bag at the grocery store.

If you take any more pictures, take them on a cloudy day or in the shade. The sun causes too much contrast and glare to see what we need to see.

My grocery store has it with the flour and Bisquick (and strangely, NOT in the international foods section), in amounts down to 2 pounds.

thank you!

2 more questions:

---do you apply cornmeal by hand or via one of those push spreaders?

--- also-will the brown areas regrow back or do they need to be reseeded or new sod laid down?

Larry, that doesn't look too bad. A couple of applications of fungicide will get that under control pretty quickly. Once the lawn starts to recover, the healthy grass will grow through the brown spots..you can always rake to dethatch it a bit, but I don't think it's necessary..

The picture below is what happened to my with my St. Augustine lawn, and it was totally my fault. I had gone out of town and the grass got really tall, cut it when I got home, whil the grass was wet. The mulch from the cut grass sat in the deck of my riding mower for a week (I should have cleaned it off). Anyway, that was enough time for the fungus to form so when I cut the grass again without cleaning the deck, it spread all over my yard.

I don't know about corn meal, but any type of organic fertilizer will help it green up..I use a product similar to milorganite that I buy at Ace.

Noticed you're watering every day for two hours, I'd say that is way too much. Like dchall said, deep, infrequent waterings are the best, twice a week should be sufficient especially with all the rain we get in Florida during the summer. I water twice a week.

For reference these pics were taken last weekend and I'm already seeing an improvement. I'm sure yours will come around as well.

I like corn meal as a fungus control because it works for me and, very importantly, there are no side effects. When you use a broad spectrum chemical fungicide you take out some of the population of beneficial fungi that normally live in the soil. Those can be replaced by minimal amounts of compost, but it's extra work. Another reason I don't like chemical fungicides is that disease in southern grasses usually happen in the heat of summer. Many (most?) fungicides have restrictions on the air temp at application. Usually that high temp is 85 degrees F. The result is the lawn gets burned back farther. At that point you don't know whether the fungicide worked or made things worse. With corn meal I can apply any day of the year and not worry about anything.

So after calling around all over Miami, somehow I have not been able to locate cornmeal. I am really trying to get this under control, so out of desperation I purchased Bayers Advanced(http://www.homedepot.com/p/Bayer-Advanced-10-lb-Granules-Fungus-Control-for-Lawns-701230/202019115). Put it down yesterday and am waiting for it to rain, to get it working.

I hope that this will work, along with having shutting off the sprinklers, and am trying to plan my next step...putting compost down? From what I see, fertilizing is the worst thing to do right about now..

In about three weeks or so, or whenever the Bayer would recommend reapplication, scatter a few pounds per thousand square feet of well-done compost evenly over the lawn.

Your natural fungi would repopulate even if you didn't, but that will speed up the process.

learn something new every day. one question, how do you keep the birds from eating all of the corn meal? lol

you're right putting the compost down creates an extra step, but it's worked for me..

personally, I haven't had any issues with the lawn burning from fungicide and we haven't seen a day below 85 since early June..

so my fungicide has been applied now for around a week, and I have a few very dark green(healthy looking) spots scattered across the yard.

It is driving me nuts that some is yellow, while a few spots are beautiful and green.

Would now be a bad time to apply minorginite to the lawn? We are having a large party middle of next month, and I am trying to get it looking just a little better....If i get a green light here, I would like to apply it ASAP

Milorganite now should not be a problem.

If you can get corn meal the birds won't even see it. If you get cracked corn, it will be all out war. I had a few bags of cracked corn sitting around so I put it on the lawn. I counted over 60 birds in my back yard at any given time! According to morpheus, you will still get benefit from the cracked corn even if a lot of it is eaten, but I say if you have a choice go with the (ground) meal.

Went ahead with Milorganite..

Would have much rather used cornmeal vs the Bayers Advanced, but somehow I have not been able to find it in Miami. Called everyone, feed stores etc. Most people had no idea what I was asking for when asking for cornmeal.

There's nothing wrong with an occasional shot of fungicide (I've had to use both Daconil and Triforine this year in the gardens and I've only managed to slow the problem down).

In about a month or so, if you can get a very small bag of compost and scatter it around at a pound or three per thousand square feet it'll help to repopulate the helpful fungi you just killed. Also, even a tiny amount of cornmeal, like you can get at the store, can help if applied to the patches and the areas immediately around them.

It's best to treat the whole lawn, but if you can't find the stuff, you do what you can.

Hum. While birds do go after it a bit, cracked corn can also serve. You can usually get that anywhere bird seed is sold. Don't use whole corn, it'll sprout a lot more often than cracked corn will, although the sprouts die easily when mowed. Still, they're annoying in gardens.

Larry - is there a Restaurant Depot near you? They have corn meal for around $22/bag. Often they will have damaged bags for half that price. If you own a business you can get a card, or if you know someone you can borrow theirs. Or, you can tell them at the desk what you want and they might give you a temp account number. They don't really care but they won't sell to you unless you have an account number.

The cornmeal you are suggesting is plain corn meal not cornmeal mix? Also, is the ground (dirt) darker than areas that don't have the problem? Help would be appreciated.

Plain corn meal. The mixes have baking powder in them to make them like Bisquick.

What about the dirt?? Spread the corn meal over the entire lawn, if that has anything to do with what you're asking.

well....turns out the damage is chinch bugs... lawn has looked worse and worse, went out last night to let me dogs out, saw a new spot-went to look and they were everywhere. Have no idea how I hadnt seen them before.

can anyone recommend a chinch bug treatment? really really frustrated

you're absolutely sure it's chinch bugs?? did you catch some, or just see some insects in the lawn and think they were chinch bugs..I was always under the impression chinch bugs attacked stressed lawns, usually under drought conditions and that is certainly not the case here..

Are you on a regular pest prevention regimen for your lawn? I use two different products, one called turf ranger (active ingredient deltamethrin) and the other called bug blaster (active ingredient bifenthrin), alternating after each application...and knock wood have not had an issue for years.

post up some more pics so we can see what your talking about.

attached is picture of some spots and overall lawn.

in one spot there are a ton of the small dark bugs which look like fleas(jump up and move around)all on green grass perimeter..

Based on the pics, I'd agree that looks like bug damage. back to my original question, do you have a pest-prevention plan in place. If not, now is the time and whatever you do will need to be applied at the highest rate to nip this in the bud..

Years ago chich bugs did a number on my lawn..I keep these pics around as a reminder, so I don't make the same mistake and now keep to a religious pest-prevention regimen..

no I do not have a plan in place, this lawn is almost brand new, we laid the sod around the beginning of July this year which is why I do not understand how chinch bugs could have taken over so quickly

Even though chinch bugs go after stressed lawns during drought, many times too much nitrogen will compromise the immune system of the turf and invite them to a feast. This time of year is not the time to apply nitrogen fertilizer, even organics such as Milorganite; too much N will aggravate the situation as to bugs and fungus, especially Brown Patch. Also, Flea beetles are mistaken for chinch bugs but are solid black and shinny and are appear to jump around (they are harmless to the grass). Chinch bugs adults are dull black with white markings that cross on their backs. With all the water that's going on, the roots are probably rotting off due to disease and lack of oxygen from the soil being so compacted. Once the soil is allowed to dry for several days, go with 2 days per week as someone suggested but be alert to shut off the sprinklers when an adequate rain of at least 1/2 inch occurs. There is a ban on nitrogen and phosphate-containing fertilizers in the summer months anyway. If you dyi, try applying a chelated trace element spray. My best advice is to hire a well-recommended licensed lawn professional to inspect the lawn and make the proper treatment.