You've heard the expression "a little knowlege can be a dangerous thing"? Well, I have just a little knowlege on the subject, so this is all just a guess. It sounds like the grass is surrounded buy concrete. Lawn, sidewalk, grass strip maybe a foot or so wide and then curb and road. Is that correct? If so, I'm betting its suffering from more heat damage than the rest of your lawn. The concrete absorbs and holds the heat and with such a small area of grass being surrounded, its just baking the roots. If you were to stick a soil thermometer in the ground there I'd bet the temp would be several degrees warmer and take longer to cool off than the ground in the middle of your yard. You might also check the pH level of the dirt there. I wouldn't be surprised if the concrete is leaching chemicals into the ground that are raising the pH and preventing the grass from being able to absorb what nutrients there are.

The local lawn and garden guru on Saturday morning radio is always talking about seeing concrete truck drivers washing off their equipment at jobsites right on the lawns or in pine islands, etc., and how this concrete residue will raise the pH in those areas for years to come making the soil very alkaline and causing it to be extremely difficult to get stuff to grow well, if at all, in those areas.

Man I wish there were an edit feature on this forum. Another question. You say you water once or twice a week, but are you watering enough each time? The grass needs at least an inch of water a week, probably a little more if you're area is suffering from the same heat wave as the midwest has been. Its preferable to water deeply once a week than less so but more often. The roots grow deeper if you water deeply and infrequently, which keeps them from drying out as readily in drought and heat wave conditions.

Thanks for reply Homechicken...yes, concrete both sides of strip...but strip is 8 feet wide. not narrow. I water around 1" total a week.

Hmm, well I doubt its heat buildup then. Could still be the second guess regarding the pH level. Why not send a soil sample off to the county extension office and see what they recommend. If the nutrient levels are good but the pH is too high or low, then that could be your problem and you can adjust the pH with sulfur to lower it or lime to raise it. If the pH is way out of whack, the nutrients may be there but the plant cannot absorb them properly. While the dirt is off being analyzed, try watering once a week long enough to put down a full inch of water instead of twice a week at a half inch each time and see if that helps. Could be the roots are just staying shallow, where the water is, and drying out. If you're suffering the extreme heat wave like a lot of the country, then maybe try more than an inch a week.

".yes, concrete both sides of strip...but strip is 8 feet wide. not narrow. I water around 1" total a week."

1" per week is a baseline. Some areas (like what you described) are just going to need more water for grass to thrive. This has just been a very hot and dry summer for most of the country and grass is suffering everywhere.

There could be an underlying fertility issue, but you are describing a classic "tough spot to grow grass". You'll probably always have to give this area a little extra TLC to make it look as nice as the rest of the lawn.

crazy_lawn:

The answer to your question was recently answered by the University of Nebraska-Lincoln Extension. Click link below.

Here is a link that might be useful: University of Nebraska-Lincoln Extension

I have to disagree with you Gary. The OP has TTTF, the article in your link states, "We do not see it (chlorosis) in tall fescue, perennial ryegrass, and some cultivars of Kentucky bluegrass (Figs. 1 and 2)". I think what you are seeing is a cumulative effect of no nitrogen fertilizer since the spring, and reduced or stopped growth rates due to the summer heat. While iron levels are important for dark green color, it isn't the only piece of the puzzle. Your iron levels aren't going to change much in a few months, your nitrogen levels will however as nitrogen leaches out of the soil much much faster. I have a TTTF lawn that lightens in the summer months, and returns to a darker color soon after my fall fertilzer application. If it doesn't return to it's former glory this fall after fertilizing then a soil test is definitely in order.

Point taken, tiemco. I overlooked the TTTF part.