Depending on how "just" replaced those areas are, it may be that the sod hasn't had time to root yet. Normally, it should be kept damp for about 2 weeks after installation (not wet, though, just damp). Then back off and water every other day for at least 2 weeks, then every third day for 2 weeks, and so on until it hits the once a week (or twice weekly) of the rest of your lawn.

Morph, it has long passed that stage. It was replaced as long ago as last October O and was growing nicely and greening up before the heat. What I don't understand is why some areas are so much more scorched than others, and also whether there is something I can do organically to prevent or protect the scorched areas from a complete brown-out.

October would mean it's still growing roots, depending on where you are. The only place getting scorched right now is down south, so I'm guessing you're way not in the PA area.

Still, roots are going to be a bit thin for the first full year. I'm going through that right now with an August-seeded lawn--we're hitting 80 for the first time today!

I'd recommend watering twice weekly, earlier in the morning or afternoon once the sun fades but early enough that the grass surface has time to dry before dark.

Striking those areas with a 150% dose of organics will encourage the soil to hold more roots and attract worms, which will help with the aeration/water retention of the soil.

Sorry, I forgot to mention that I am in Central Florida, zone 9a/b - Orlando. Temps have been in the high 80's this week
I do water twice weekly, early but I will try to put more organics in especially at the problem spots and see if that helps!

What type of grass do you have?

At what height are you mowing?

How much (in inches) are you currently watering?

Drought-like conditions can occur in sandy Florida soils after only a few days without rain. We haven't had rain for a few weeks. To make sure that your lawn can cope with drought like conditions, you may need to alter maintenance practices.

Skoot: grass: St. Augustine (what else would give so much trouble?); mowing height 4inches; water; twice weekly (as allowed) 1 hour in each zone= 1 inch twice weekly.

I also have St. Aug and live due west of you. My grass does/has been doing the same thing. I usually can go anywhere between 5-7 days between waterings. My grass wilts (gets scorched looking) by the street and driveway first. Plus a few other spots around the lawn. At the 3rd - 4th day after I irrigate, and most noticeable by late afternoon the grass blades are completely curled/wilted looking. Lawns under drought stress curl up their leaves to reduce the amount of surface area and conserve water. By the next morning the grass blades have returned to normal. I usually let it do this for 2-3 more days until I irrigate.

Does this sound like you situation? If so, this is completely normal of all turf grasses.
If by the next morning your lawn is still wilted, its time to water.

Are you sure your applying 1" of water?
Is you irrigation system applying water uniformly?
What time of day are you watering?

Lawns should be irrigated when 30 to 50 percent of the lawn shows signs of wilt.

OK, Florida. Please disregard everything I just said, except about the organics, which any grass can use....

Skoot - thanks for your response. Yes, your situation sounds exactly like mine. The problem is that after a couple days of scorch it becomes brown and brown is dead or close to dead. My sprinklers do deliver the water but how evenly I am not sure. I am at a corner so I have placed hoses at both sides of the house and plan to use an attached sprinkler as needed. In my experience, no one has been able to adjust the inground sprinklers so that everywhere gets evenly watered.
Anyway, it's good to know that this somewhat normal - my joints and I just get terrified of having to replace so much grass yearly.

Can you post a pic or 2 of the trouble area?
One close up and one from a distance?

Your correct in that no irrigation is perfectly uniform. But some designs are worse than others. You might want place several tuna cans throughout your zone. Place them in the good and bad areas. Run your irrigation as you normally would. Then go measure each can and write down the results. You might be surprise.

The only other thing I can tell you to do is watch it closely, and apply water only when needed. Also apply lots of organic matter. Homemade Compost, Used Coffee grounds, etc etc. If you have any bags of Leafs from fall spread them on the trouble spots and mulch mow over them.

rosarama, you mention 'several scorched areas'. Are they close to each other or apart? If they are close to each other it may be a localised ground condition. The commonest cause is the builder dumping/burying stuff usually in the front yard. The condition is quite noticeable in the newer subdivisions in this time of drought. Are the patches round, curved or angular. Round patches can mean fungus if more watering was given to the area. Angular patterns can indicate shortfall in the irrigation system. Take four quarters (representing four full circle irrigation heads) and place them on a sheet of paper in a circle with their sides touching; pencil-shade that curved diamond shape in the center and remove the coins. If that shaded pattern resembles any of the patches it indicates that the irrigation heads are not overlapping.
In general, straight lines and angles indicate abiotic factors. It is possible that there is a physical condition like compaction that is causing the problem. Dig down a bit and see if such a condition exists. Finally, to eliminate insects, do a soap flush over a couple of areas covering that border of good and bad turf. Under these weather conditions, I'd be looking for chinch bugs. The adults are black but the young are red.
One of the great advantages of St. Augustine grass is that you can encourage it to cover a bare area by putting down something organic like good top soil and watering at the transition zone, the healthy runners grow out and root fairly quickly. All is never lost with St. Augustine.
That last remark will trigger some repartee shots from..... Is it bpgreen or bestlawn... ?

I would be on the phone looking for ordinary corn meal or cracked corn and doing what roanlawn82 said. If you have a fungus disease, the corn meal will take care of it. If you don't then you have a little more fertilizer down. But uneven watering is very common and will look like a scorched area week after week.

I use an above the ground oscillating sweep type sprinkler. I went back to that last year and I love it.

Sorry guys, I was away and came back so sick with the flu or some bug, Iwas out of commission for the past three weeks.
The areas (and they are close to driveway and the sidewalk) eventually turned green once we had a a few showers of rain. One more week of drought and they turned completely brown which was reminiscent of last year's attach of chinch bugs - and in the ssame areas too. DH treated last weekend with wome supposedly organic stuff (Organicide from OMRI) and it was obvious that whatever was happening was stopped in its tracks.
My take on this is that the areas wee originally dry from lack of water and that the bugs attacked these areas first.
There are still areas of green and I am hoping the brown patches still have some life in the roots.
These bugs are enough to make me forget about organic but I am searching for rosemary oil which I have hard can take care of chinch bugs. Does anyone know where this can be found and how it is used?
Thjanks to all for your helpfulness and good advice.

You say the affected areas are near the driveway and side walk? Might be a good idea to test the soil in that area. Maybe due to a ph problem with lime leaching from cement. Or depending on elevation layout surface contaminants running off into the area.