I know Florida's heat can cause misery to some lawns....but you are not doing your grass any favor by watering as much as you are. What you are saying is.....grass needs water...the more the better. You are drowning the roots which, once they have taken in as much as they can use, then cant take in anymore, the water sits there and rots the roots.....killing the grass above., I'll grant you some grasses need more tha others....and some grasses, no matter how much water you give it....will turn yellow in the fall to return to its green int he spring. Bermuda grass, I believe is one of these. St Augustine grass will put up with some drought during dry spells. Try watering your lawn when the grass can take it in. This is a fact. Too much watering causes grass roots to be stunted.....it dies when the sun's heat hits. Too little watering causes grass roots to be stunted....it dies when the sun's heat hits. You have to find the happy medium..

You tricked me. I was going to guess that you lived in Texas (calcium soil) and have been subject to the heavy rains we've had over the past few weeks. Still you have the same issue. Your soil needs iron. I would start with Milorganite fertilizer. Give that 3 full weeks and see how it looks then. If it seems to be a little better, repeat. If you can find a product with glauconite, use that at 40 pounds per 1,000 square feet. In Texas it's called Texas Greensand, but sometimes they leave the Texas off. It is a greenish sandy material that is rich in all kinds of minerals. It works to green up this washed out soil when nothing else works. Do you know how much water your system puts out in 5 minutes? The best watering schedule for you would be to water 1 full inch, all at one time, and do that once every 1-2 weeks depending on whether your temps are in the 90s or 80s. Put some cat food or tuna cans around the yard, turn on the sprinklers and time how long it takes to fill the cans. That's how long you should be watering every week or two. You cannot go cold turkey with this watering if your grass is currently getting almost daily water. That would kill it because your roots are only as deep as they need to be to get that almost daily dose of very little water. Deeper and less frequent watering will develop deeper roots which are able to get iron at greater soil depths. If you are currently watering 4x per week, try watering deeply (during your can test), and then watch the grass carefully to see how long it can go without looking wilted. At the first sign anywhere of wilting, water it again for half the time it takes to get the inch. Then watch again and water 1/2 inch at the first sign of wilting. Now the grass should start to go longer before it looks wilted. When the grass can go 4 days without water, then give it a full inch and repeat the same regimen of watching for wilting. Soon enough it should go a week to 10 days before wilting. Then you can adjust your schedule. But at no time should you be watering more than once per week. And why do I say all that. Weed seeds need continual moisture to germinate and take root. When you water every other day, the weed seeds get exactly what they need. If you allow the surface of the soil to dry out completely before you water again, the weeds can't get started. You'll end up using less water, less fertilizer, and just about zero herbicide.

Do you happen to live to the northeast of Springfield...sort of near that gigantic limestone quarry? I have a feeling that you could apply 1,000 pounds of sulfur per square inch from now on and never change your pH enough to make a difference. First you would have to dissolve all the limestone. Which means you'll have to adjust your expectations a little - but not much. When iron hits calcium at high pH numbers, the iron binds to the calcium and will not release to the plants. When the pH drops a little the iron is released and available to the grass. I'm an organic kind of guy so the first thing I look at is what the soil microbes can do for you. When they are well fed they can acidify the soil right at the root zone. That's where you need it. But when you get a gully washer of a rain storm, the excess water will wash that acidity out leaving you with something like what you have. We get that in Texas (limestone quarries everywhere). If you have something like we have then in the spring you will never know it was yellow. Something happens in the soil over the winter to release the iron. My belief is the microbes are busy acidifying the soil. It happens every year, so it's nothing I've done. One product we use down here to counteract the effect of the rain washing through is to apply green sand. Green sand is a complex assortment of minerals that has the consistency of sand and a dark olive drab color - hence the name. At a rate of 40 pounds per 1,000 square feet it will correct the soil and green up the grass. I would not use it at this time of year, because I'm certain your lawn will look great in April regardless of anything you try now. But keep that in the back of your mind. Your normal fertilizer schedule should be once in May, once in September, and once after the grass stops growing in the fall. Keep that in mind when talking to lawn maintenance companies. Weeding should be done on an individual basis. That means they spot spray the weeds and DO NOT apply a broadcast type of herbicide over the entire lawn. In addition to what the company applies, I would encourage you to apply at lease one dose of an organic fertilizer. On this and many other forums we use raw animal feed like soybean meal, corn meal, alfalfa pellets (rabbit sized), cottonseed meal, or whatever kind of ground up nut, bean, or seed you can find at your local feed store. The application rate is 15 - 20 pounds per 1,000 square feet. What this does is feed the microbes living in your soil. If they are not happy, then you will not be happy with your lawn. Once a year is enough, but I use it exclusively about 5 times per year. You can do what you want with that. Most of the serious grass gurus in the forums are 90-100% organic with fertilizer. You said you did not over or under water. Since you were just establishing a new lawn I'll let that go. As the weather warms up in the spring, you should water approximately once in March and April. In May, as the temps get into the 70s go to once every 3 weeks. When the temps get into the 80s go to once every 2 weeks. When it's in the 90s all week, go to once per week. When you water apply a full inch all at one time. Set out some tuna or cat food cans and time how long it takes your sprinklers to fill all the cans. That is your watering time. Mine takes 8 hours but my neighbor's high flow system takes only 20 minutes. Your time likely will be between those extremes. That time will be how long you water EVERY time you water from now on. That's the secret to infrequent watering and infrequent watering is the secret to having very few weeds. DO NOT LET ANYONE TALK YOU INTO WATERING A LITTLE BIT EVERY DAY. Here's an incentive picture for you on that topic. The picture was taken in July. Most everyone waters once a day except one.

Spotty higher pH can happen if you got the soil off of one particular section of the pile...that happened to contain the old B horizon with some limestone in it! In my case, I got the old subsoil on my lot, so it just kind of stank all around. * You said you targeted our phosphorus level higher than your own lawn. Is this due to the pH difference or something else? Is phosphorus bound in the soil at higher pH's, and is our pH (7.1 - 7.3) high enough to cause that? pH. If you look at the availability of P by pH, it drops as pH rises above seven. You're not that far over, the binding isn't extreme, so I just boosted the numbers a little bit. Your standard is around 220, most people with slightly acidic pH would be around 200. In your case, I wouldn't blink at anything between 200 and 300. I never use my own soil as a standard, per se, for anybody else's. Mine have given in to some experimental stuff, plus I've over-enhanced the gardens to match the (extreme) density and (extraordinarily high) performance I demand they support. My current P levels in the garden push 1,000. * What kind of quality issues can we expect from the low phosphorus level until it's corrected? Thin, weak, sparse growth that gets sick and dies easily, discolors easily, grows poorly, and generally doesn't look at all good. Installed sod would tend to thin out and die back over the course of a year or so if it isn't corrected, resulting in a lot of thin patches and blank areas. N, P, and K are the big three and absolutely have to be there in the correct proportions (N we take care of on an as-needed basis). * It sounds like the Milorganite is great stuff, but I'm very sensitive to odors, so I don't think it's a good fit for our lawn. If we used ferrous sulfate instead (being careful to sweep it off the concrete), what rate and frequency would you recommend? I assume we don't need to worry about lowering the soil pH too much with the ferrous sulfate since the starting pH is above 7.0. I'd be comfortable with ferrous sulfate (monohydrate or pentahydrate, it doesn't matter) at 3 pounds per thousand square feet in April, early October, and perhaps early November if the weather's holding. Keep an eye on the pH in this case, though, as iron sulfate is about an eighth as acidifying as pure elemental sulfur and does NOT require digging in to work! Never use iron during hotter months or when the soil's going to freeze solid for winter within two or three weeks of use.