My St. Augustine grass had developed yellow spots here and there. Nitrogen fertilizer did not help much. Besides, I did not want to add much Nitrogen to my grass to avoid excessive growth and potentially an increased risk of lawn disease later on. I had used other liquid-iron products before, which local garden stores stopped selling long ago for some reason.I found this product on Amazon and gave it a try. My liquid iron arrived promptly. I sprayed it at just a little higher concentration than what the product calls for. I set my hose sprayer to 4 tbps/gal. I used about three fourths of it watering my lawn and flower beds.In a matter of four days, my grass has turned into a beautiful, even dark green throughout. As I expected, this was an amazing and beautiful improvement to my lawn. Once again, I have the greenest, prettiest lawn in my area. Yes, it is a little pricey, but well worth the money. The grass hasn't taken off growing, either. It is a win-win.The manufacturer warns against this product severely staining sidewalks, but I was very careful to apply it only to my grass as much as possible. There was some overspray into my driveway and sidewalk, but I do not see any signs of iron stains at all.Once again, I have a beautiful, solidly green lawn thanks to this amazing product. Liquid Iron is the way to go for me. I will buy some more and reapply at a later date. STRONGLY recommended.August 31, 2017My St. Augustine had turned yellow in several areas of my yard. A severe case of iron chlorosis. I knew that fertilizer would not fix this, no matter which kind. Once again, I applied this prized medicine to my lawn. TWO DAYS later, all the yellow St. Augustine is just gone! My lawn now has that beautiful dark green hue everywhere.I used my hose-end sprayer, set the dial to 1 oz. and sprayed away, always careful, of course, not to hit the sidewalk or walls. For it will stain them brown.not 5. 10 stars! Guaranteed results with St. Augustine, period.