Sounds like you are spreading the sulfur over the surface. If I were you, unless your pH is over 8, I would just wait until your lawn is established to put down sulfur. A good time is in the fall after core aeration. Sulfur is converted to sulfuric acid via soil microbes. Who knows if that will hurt delicate seedlings or not, but why risk it? Unless your pH is extremely out of wack, your seed will germinate and grow just fine. You will have plenty of time later to *attempt* to lower your soil pH. How high is your pH?

If you spread the sulfur on the surface, you may not see a lot of benefit from it. It really needs to get into the soil to do much good. And it takes quite a while for it to help, also. Are you trying to lower the pH over a large area? If so, you may have better luck by increasing the organic content of your soil. I used a bulb auger to drill holes around the drip line of a chlorotic maple. I used about 50 lbs of sulfur just for that one tree. It helped to an extent, but I think what has helped more is the amount of organic matter I've been adding over the past few years.

It almost sounds like Hadacol at times (pH too high? OM! too low? OM! too much clay? OM! too much sand? OM!), but increasing the OM can really cure an awful lot of woes.

Oh, by the way, for your parents' low pH, I'd recommend that they try to increase the OM in their soil.

My lawn is fully established and I was just going to overseed. My pH is 7.5. My OM % is very low, so I guess I will just try that this year. I'm trying to lower the pH across my entire lawn (about 9500 sq. ft.).

I can't remember the % of OM in my parents lawn, but it is very high and they have a pH of 5.0 - 5.3 in various places in their lawn. The lawn there has been mulch mowed for the last 24 years (and re-planted from scratch several times, with the most recent being last fall with a blend of FF), so it's not surprising the OM % is high there. But, you're saying if the OM % is high, then the there shouldn't be any problems with the pH? The soil test they had done said to add quite a bit of lime over the next couple of years.

I don't think you'll be happy with the results you'll get by spreading sulfur on the surface. I think you'll get much better results just by increasing the organic content. Even if the pH stays fairly high, you'll see improvements because of the buffering effect of the organic matter.

Also, with a pH of 7.5, I wouldn't bother trying to add iron unless you have an actual iron deficiency in the soil. If you add iron to soil that alkaline, it won't be available to the grass, anyway (unless you use eddha chelated iron, and that would be prohibitively expensive). You can use a foliar spray when it's not too hot, since the grass can benefit from the iron that is absorbed through the leaves, but that will have a very short term effect.

My soil is usually alkaline also. I never used straight sulfur for reasons that it is easy to burn the lawn and it does not last. I fertlize with ammoniun sulfate and the grass looks great. Good luck.

Thanks for the tip, dought. I've looked for that around here before, but was unable to find it. Where do you get yours?

I use ammonium sulfate in the fall. I have a pH above 8 here in Colorado with my KBG. And I have no problem getting the turf to respond to iron. I use a fertilizer that has ferrous sulfate as its iron source. It does much better than iron sucrate in my basic soil, although it leaves rust spots on the sidewalk if I don't blow it off really well. It's a 24-5-11 with 50%PPSCU and 3% Ferrous Sulfate. I get it at Lesco/John Deere Landscapes.

Where do you guys get the ammonium sulfate? I've tried ferrous sulfate as a separate application for my slightly high pH--both for the iron and to a lesser extent the sulfur (20% Fe, 11% S). I put down about 2.5lb/1000sq.ft. Price is not too bad at EHGriffith (where I seem to get a lot of supplements), seeing as how i cannot find it locally. You can also use it as a foliar spray and thereby bypass any soil limitations. The granules looked almost white to me, so despite the warnings, I did not sweep it off my sidewalks--man does the stuff stain!

"Where do you guys get the ammonium sulfate?"

Home Depot and WalMart both carry it here.

eriocaulon, how did your application of ferrous sulfate work? I've never heard of that before, but it sounds like it attempts to kill two birds with one stone (acidifying the soil, while adding iron).

Nice greenup I would say, and seems to last longer than foliar spraying--although my spray technique is not optimal. I have also used the following linked product but it is no longer easy for me to find--my local Lesco happen to have 2 bags in stock a couple of years ago. My pH has come down over the last few years (7.7 in 2004, 7.4 in 2007), although slowly. Not sure if the trend will continue--I am going to get a soil test this year.

also, aeration is good for iron uptake, and also avoidance of excess phosphorus--get soil test if unknown.

Here is a link that might be useful: Disper-Sul

I get mine from a local feed store. Look for a store that supplies farmers with their fertlizing needs. It's much cheaper than regular fertlizer. And that is what it is used for, so don't put ammonium sulfate down and then use a nitrogen fertizer at the same time. Other wise you just fertlized your lawn twice. Good luck. Doug.

Thanks for the info, guys. We have a couple of feed stores around here, so I'll be checking them out. Might end up being a good place to buy SBM, too. I am trying to go organic this year (except for the last feeding of the year).

Well, excluding the apps of ferrous sulfate or ammonium sulfate :-). I'm trying to just find the ferrous sulfate.

If you find iron sulfate, that's the same thing as ferrous sulfate, just a different name.

Ammonium sulfate is in all fast acting I'm assuming. How much nitrogen do you put down? 0.5lb/1000sqft at a time--good for 30 days? I might try some in the fall if I can find it. Thanks for the tip on the feed store. My HD/lowes/Walmart definitely do not carry it.