Someone will be along soon and give you the particulars regarding using baby shampoo as a surficant. I have no experience with it but they swear by it.

I had some issues like you, a few areas near the street, sandy soil, slight slope, and water would just run off, and there was little penetration. It sounds crazy, but the shampoo trick worked for me, and the grass filled in very quickly after a few treatments and some rain. It's so easy and cheap you really have nothing to lose. Baby shampoo is good, but I use cheap VO5, or White Rain. You want a clear shampoo, with no additives, just a basic cheap shampoo. Put it in a hose end sprayer and apply at 3 oz. per gallon. I like to dilute it by 100% and apply at 6 oz. per gallon. Spray the areas liberally. Once you have sprayed all the areas you want (you can do the whole yard even if you want) then irrigate the areas lightly by hand to work the shampoo into the soil a bit and wash it off the grass blades. You might have to repeat it a few times, but it really helped my problem areas. A secondary benefit is your lawn will smell great.

3 oz. per gallon? I don't think so.

Don't see what you are getting at nearandwest. You don't like the process or are you disagreeing with the proportions?

That's the rate I used on my hose end sprayer, well I used 6, but I dilute 100%.

So what I am reading here is that for every gallon of water that is coming out of a hose-end sprayer, it is being mixed with 6 oz. of shampoo at a 100% dilution rate?

Not exactly. If you use straight shampoo, then the recommended rate is 3 oz. of shampoo for every gallon. If you dilute it 100%, then you are using 6 oz. of shampoo/water solution per gallon of water, which is still 3 oz. of shampoo for every gallon of water that comes out of the hose. I personally think you get better "pull" when you dilute it. It goes pretty fast, so you have to spray relatively light if you are doing large areas, then go back over it with just plain water.

And how many gallons of water per 1000 sq.ft. are you applying out of this hose-end sprayer?

I believe hose end sprayers, like Ortho, have settings for application of material calibrated for coverage of a 1000sq ft. area, so most likely, you select an application rate of 3oz on the sprayer and move the spay just once over an area of grass and keep moving. But it's just a guess, I'm going to buy one tomorrow and I'll find out.

I really don't treat it like I am doing X amount per 1000 square feet. I just spray problem areas till I think they are well covered. Like I said, it goes pretty fast and usually I am applying a lot more than 3 oz. per 1000 for sure. The last time I used shampoo I probably did about a quarter to a third of the yard near the street with one bottle, so that's way more then 3 oz. per 1000, more like 24. It's really more of a feel thing for me, not a critical dosage like herbicides and fertilizers. For me the 3 oz per gallon makes it last longer, and more dilute, so it gets to the soil better. If I set it to the real amount I use it would be gone very quickly.

Ok tiemco, you answered to the point I was trying to make. Everything I have ever seen about the generic shampoo treatment for softening soil (usually from dchall on this forum) indicates a rate of 3 oz./1000 sq.ft. In your initial posted response above in this thread, you were recommending the rate of 3 oz./Gallon of water. Those two rates can be equal if properly calibrated, but usually are not. When it comes to pesticides or fertilizers, the difference between those two rates can be very significant. However, when it comes to baby shampoo, as you previously stated, it is not as critical of a dosage. Thank you for the complete clarification in your most recent post. I knew you would eventually get there.

And again, 3 oz./1000 is not the same as 3 oz./Gallon unless a sprayer or applicator is properly calibrated!

No wonder there are so few people on this forum.

I thought that was the direction you were going Nearandwest, 3 oz. per gallon per 1000 would have a very small effect, so for all you people that want to try this the amount you put down isn't very critical, just until the soil is wet, then go over it again with plain water.

Thanks for the suggestions everyone. I was thinking about just digging up the bad part of the lawn and re-sodding after adding lots of compost. I think I will try the shampoo idea over a section of the lawn.

How long it would take before I see some results?

thanks again all!

You should see better water penetration/retention after the first treatment. My worst area had a lot of bare patches. Since using the shampoo it has filled in within a month, and this is tall fescue, which is not known for spreading, although the cultivars I used are some of the newest ones that have higher rhizome activity.

tiemco: Even though I rarely post on this forum any more, I continue to enjoy reading your insightful and informative comments, which are almost always spot on.

Thanks nearandwest. Flattery will get you everywhere. I am accepting donations by the way.